diff --git a/src/components/introduce/IntroduceHeader.jsx b/src/components/introduce/IntroduceHeader.jsx
index 6909f17..0c0de51 100644
--- a/src/components/introduce/IntroduceHeader.jsx
+++ b/src/components/introduce/IntroduceHeader.jsx
@@ -24,7 +24,7 @@ const IntroduceHeaderWrapper = styled.div`
 `;
 
 const IntroduceHeader = ({
-  group, onApply, user, realTime, onApplyCancel, onChangeApplyFields, applyFields,
+  group, onApply, user, realTime, onApplyCancel, onChangeApplyFields, applyFields, clearForm,
 }) => {
   const [loginCheckModal, setLoginCheckModal] = useState(false);
   const [applyCancelModal, setApplyCancelModal] = useState(false);
@@ -69,6 +69,7 @@ const IntroduceHeader = ({
 
   const handleFormCancel = () => {
     setModalForm(false);
+    clearForm();
   };
 
   return (
diff --git a/src/components/introduce/IntroduceHeader.test.jsx b/src/components/introduce/IntroduceHeader.test.jsx
index 2260338..124c174 100644
--- a/src/components/introduce/IntroduceHeader.test.jsx
+++ b/src/components/introduce/IntroduceHeader.test.jsx
@@ -9,6 +9,7 @@ import STUDY_GROUP from '../../../fixtures/study-group';
 describe('IntroduceHeader', () => {
   const handleApply = jest.fn();
   const handleApplyCancel = jest.fn();
+  const handleClearForm = jest.fn();
 
   beforeEach(() => {
     jest.clearAllMocks();
@@ -18,10 +19,11 @@ describe('IntroduceHeader', () => {
     <IntroduceHeader
       user={user}
       group={group}
-      applyFields={{ reason: '', wantToGet: '' }}
+      applyFields={{ reason: 'reason', wantToGet: 'reason' }}
       realTime={time}
       onApply={handleApply}
       onApplyCancel={handleApplyCancel}
+      clearForm={handleClearForm}
     />
   ));
 
@@ -214,7 +216,6 @@ describe('IntroduceHeader', () => {
 
           fireEvent.click(button);
 
-          // TODO: 이 부분은 추후 변경해야된다 현재 스터디 참여 신청서 모달창이 나타남.
           fireEvent.click(getByText('확인'));
 
           expect(handleApply).toBeCalled();
diff --git a/src/components/introduce/modals/ApplicationFormModal.jsx b/src/components/introduce/modals/ApplicationFormModal.jsx
index 37c6947..9aa16cb 100644
--- a/src/components/introduce/modals/ApplicationFormModal.jsx
+++ b/src/components/introduce/modals/ApplicationFormModal.jsx
@@ -1,4 +1,4 @@
-import React from 'react';
+import React, { useState } from 'react';
 
 import styled from '@emotion/styled';
 
@@ -96,6 +96,13 @@ const ContentTextareaWrapper = styled.textarea`
   &:focus {
     border: 2px solid ${palette.teal[5]};
   }
+
+  ${({ error }) => error && css`
+    &::placeholder {
+      color: ${palette.warn[1]};
+    }
+    border: 2px solid ${palette.warn[1]};
+  `};
 `;
 
 const StyledButton = styled(Button)`
@@ -107,14 +114,37 @@ const StyledButton = styled(Button)`
 const ApplicationFormModal = ({
   visible, onCancel, onConfirm, onChangeApply, fields,
 }) => {
+  const [error, setError] = useState(null);
+
   const { reason, wantToGet } = fields;
 
   const handleChange = (e) => {
     const { name, value } = e.target;
 
+    setError(null);
     onChangeApply({ name, value });
   };
 
+  const handleCancel = () => {
+    setError(null);
+    onCancel();
+  };
+
+  const handleConfirm = () => {
+    if (!reason.trim()) {
+      setError('reason');
+      return;
+    }
+
+    if (!wantToGet.trim()) {
+      setError('wantToGet');
+      return;
+    }
+
+    setError(null);
+    onConfirm();
+  };
+
   if (!visible) {
     return null;
   }
@@ -126,6 +156,7 @@ const ApplicationFormModal = ({
         <ContentBoxWrapper>
           <label htmlFor="apply-reason">신청하게 된 이유</label>
           <ContentTextareaWrapper
+            error={error && error === 'reason'}
             rows="10"
             id="apply-reason"
             name="reason"
@@ -137,6 +168,7 @@ const ApplicationFormModal = ({
         <ContentBoxWrapper>
           <label htmlFor="study-want">스터디를 통해 얻고 싶은 것은 무엇인가요?</label>
           <ContentTextareaWrapper
+            error={error && error === 'wantToGet'}
             rows="10"
             id="study-want"
             name="wantToGet"
@@ -146,8 +178,8 @@ const ApplicationFormModal = ({
           />
         </ContentBoxWrapper>
         <div className="buttons">
-          <StyledButton onClick={onCancel}>취소</StyledButton>
-          <StyledButton success onClick={onConfirm}>확인</StyledButton>
+          <StyledButton onClick={handleCancel}>취소</StyledButton>
+          <StyledButton success onClick={handleConfirm}>확인</StyledButton>
         </div>
       </ModalBoxWrapper>
     </ApplicationFormModalWrapper>
diff --git a/src/components/introduce/modals/ApplicationFormModal.test.jsx b/src/components/introduce/modals/ApplicationFormModal.test.jsx
index bb9479a..7f023ad 100644
--- a/src/components/introduce/modals/ApplicationFormModal.test.jsx
+++ b/src/components/introduce/modals/ApplicationFormModal.test.jsx
@@ -9,6 +9,10 @@ describe('ApplicationFormModal', () => {
   const handleConfirm = jest.fn();
   const handleChange = jest.fn();
 
+  beforeEach(() => {
+    jest.clearAllMocks();
+  });
+
   const renderApplicationFormModal = ({ visible, fields }) => render((
     <ApplicationFormModal
       visible={visible}
@@ -20,50 +24,94 @@ describe('ApplicationFormModal', () => {
   ));
 
   context('with visible', () => {
-    const modal = {
-      visible: true,
-      fields: {
-        reason: '',
-        wantToGet: '',
-      },
-    };
+    context('with applyFields value', () => {
+      const modal = {
+        visible: true,
+        fields: {
+          reason: 'reason',
+          wantToGet: 'wantToGet',
+        },
+      };
 
-    it('renders Modal text', () => {
-      const { container } = renderApplicationFormModal(modal);
+      it('renders Modal text', () => {
+        const { container } = renderApplicationFormModal(modal);
 
-      expect(container).toHaveTextContent('스터디 참여 신청서 📚');
-      expect(container).toHaveTextContent('신청하게 된 이유');
-      expect(container).toHaveTextContent('스터디를 통해 얻고 싶은 것은 무엇인가요?');
-    });
+        expect(container).toHaveTextContent('스터디 참여 신청서 📚');
+        expect(container).toHaveTextContent('신청하게 된 이유');
+        expect(container).toHaveTextContent('스터디를 통해 얻고 싶은 것은 무엇인가요?');
+      });
 
-    it('calls confirm event action', () => {
-      const { getByText } = renderApplicationFormModal(modal);
+      it('calls confirm event action', () => {
+        const { getByText } = renderApplicationFormModal(modal);
 
-      const button = getByText('확인');
+        const button = getByText('확인');
 
-      fireEvent.click(button);
+        fireEvent.click(button);
 
-      expect(handleConfirm).toBeCalled();
-    });
+        expect(handleConfirm).toBeCalled();
+      });
+
+      it('calls cancel event action', () => {
+        const { getByText } = renderApplicationFormModal(modal);
 
-    it('calls cancel event action', () => {
-      const { getByText } = renderApplicationFormModal(modal);
+        const button = getByText('취소');
 
-      const button = getByText('취소');
+        fireEvent.click(button);
 
-      fireEvent.click(button);
+        expect(handleCancel).toBeCalled();
+      });
 
-      expect(handleCancel).toBeCalled();
+      it('change apply form fields', () => {
+        const { getByLabelText } = renderApplicationFormModal(modal);
+
+        const input = getByLabelText('신청하게 된 이유');
+
+        fireEvent.change(input, { target: { name: 'reason', value: '내용' } });
+
+        expect(handleChange).toBeCalled();
+      });
     });
 
-    it('change apply form fields', () => {
-      const { getByLabelText } = renderApplicationFormModal(modal);
+    context('without applyFields value', () => {
+      it("doesn't reason value", () => {
+        const modal = {
+          visible: true,
+          fields: {
+            reason: '',
+            wantToGet: 'wantToGet',
+          },
+        };
+
+        const { getByText, getByLabelText } = renderApplicationFormModal(modal);
+
+        const button = getByText('확인');
+
+        fireEvent.click(button);
+
+        expect(handleConfirm).not.toBeCalled();
+
+        expect(getByLabelText('신청하게 된 이유')).toHaveStyle('border: 2px solid #ff8787;');
+      });
+
+      it("doesn't wantToGet value", () => {
+        const modal = {
+          visible: true,
+          fields: {
+            reason: 'reason',
+            wantToGet: '',
+          },
+        };
+
+        const { getByText, getByLabelText } = renderApplicationFormModal(modal);
+
+        const button = getByText('확인');
 
-      const input = getByLabelText('신청하게 된 이유');
+        fireEvent.click(button);
 
-      fireEvent.change(input, { target: { name: 'reason', value: '내용' } });
+        expect(handleConfirm).not.toBeCalled();
 
-      expect(handleChange).toBeCalled();
+        expect(getByLabelText('스터디를 통해 얻고 싶은 것은 무엇인가요?')).toHaveStyle('border: 2px solid #ff8787;');
+      });
     });
   });
 
diff --git a/src/containers/introduce/IntroduceContainer.jsx b/src/containers/introduce/IntroduceContainer.jsx
index 856f6d4..472a274 100644
--- a/src/containers/introduce/IntroduceContainer.jsx
+++ b/src/containers/introduce/IntroduceContainer.jsx
@@ -5,7 +5,7 @@ import { useDispatch, useSelector } from 'react-redux';
 
 import { getAuth, getGroup } from '../../util/utils';
 import {
-  changeApplyFields, deleteParticipant, loadStudyGroup, updateParticipant,
+  changeApplyFields, clearApplyFields, deleteParticipant, loadStudyGroup, updateParticipant,
 } from '../../reducers/groupSlice';
 
 import StudyIntroduceForm from '../../components/introduce/StudyIntroduceForm';
@@ -41,6 +41,10 @@ const IntroduceContainer = ({ groupId }) => {
     dispatch(changeApplyFields({ name, value }));
   }, [dispatch]);
 
+  const clearApplyForm = useCallback(() => {
+    dispatch(clearApplyFields());
+  }, [dispatch]);
+
   if (!group) {
     return (
       <GroupContentLoader />
@@ -56,6 +60,7 @@ const IntroduceContainer = ({ groupId }) => {
         applyFields={applyFields}
         onApply={onApplyStudy}
         onApplyCancel={onApplyCancel}
+        clearForm={clearApplyForm}
         onChangeApplyFields={onChangeApplyFields}
       />
       <StudyIntroduceForm
diff --git a/src/containers/introduce/IntroduceContainer.test.jsx b/src/containers/introduce/IntroduceContainer.test.jsx
index 5f4795b..4c5609f 100644
--- a/src/containers/introduce/IntroduceContainer.test.jsx
+++ b/src/containers/introduce/IntroduceContainer.test.jsx
@@ -86,8 +86,8 @@ describe('IntroduceContainer', () => {
     given('group', () => (STUDY_GROUP));
     given('user', () => ('user'));
     given('applyFields', () => ({
-      reason: '',
-      wantToGet: '',
+      reason: 'reason',
+      wantToGet: 'wantToGet',
     }));
 
     it('click event dispatches action call updateParticipant', () => {
@@ -101,7 +101,6 @@ describe('IntroduceContainer', () => {
 
       fireEvent.click(button);
 
-      // TODO: 이 부분은 추후 수정해야된다. 현재 스터디 참여 신청서 모달창으로 인해 테스트 fail되기 때문에 변경해놈
       fireEvent.click(getByText('확인'));
 
       expect(dispatch).toBeCalledTimes(2);
diff --git a/src/reducers/groupSlice.js b/src/reducers/groupSlice.js
index a052471..7cf5185 100644
--- a/src/reducers/groupSlice.js
+++ b/src/reducers/groupSlice.js
@@ -76,6 +76,13 @@ const { actions, reducer } = createSlice({
         draft.applyFields[name] = value;
       });
     },
+
+    clearApplyFields(state) {
+      return {
+        ...state,
+        applyFields: applyInitialState,
+      };
+    },
   },
 });
 
@@ -86,6 +93,7 @@ export const {
   clearWriteFields,
   successWrite,
   changeApplyFields,
+  clearApplyFields,
 } = actions;
 
 export const loadStudyGroups = (tag) => async (dispatch) => {
@@ -142,6 +150,7 @@ export const updateParticipant = ({ reason, wantToGet }) => async (dispatch, get
   });
 
   dispatch(setStudyGroup(newGroup));
+  dispatch(clearApplyFields());
 };
 
 export const deleteParticipant = () => async (dispatch, getState) => {
diff --git a/src/reducers/groupSlice.test.js b/src/reducers/groupSlice.test.js
index 501007d..51262db 100644
--- a/src/reducers/groupSlice.test.js
+++ b/src/reducers/groupSlice.test.js
@@ -15,6 +15,7 @@ import reducer, {
   updateParticipant,
   deleteParticipant,
   changeApplyFields,
+  clearApplyFields,
 } from './groupSlice';
 
 import STUDY_GROUPS from '../../fixtures/study-groups';
@@ -151,6 +152,24 @@ describe('reducer', () => {
       expect(state.applyFields.reason).toBe('참여합니다.');
     });
   });
+
+  describe('clearApplyFields', () => {
+    const initialState = {
+      applyFields: {
+        reason: '타이틀',
+        wantToGet: '내용',
+      },
+    };
+
+    it('clears fields of application', () => {
+      const state = reducer(initialState, clearApplyFields());
+
+      const { applyFields: { reason, wantToGet } } = state;
+
+      expect(reason).toBe('');
+      expect(wantToGet).toBe('');
+    });
+  });
 });
 
 describe('async actions', () => {
@@ -237,7 +256,7 @@ describe('async actions', () => {
       wantToGet: '원하는 것',
     };
 
-    it('dispatches setStudyGroup', async () => {
+    it('dispatches setStudyGroup and clearApplyFields', async () => {
       await store.dispatch(updateParticipant(applyFields));
 
       const actions = store.getActions();
@@ -250,6 +269,7 @@ describe('async actions', () => {
           confirm: false,
         }],
       }));
+      expect(actions[1]).toEqual(clearApplyFields());
     });
   });