diff --git a/system-variables.md b/system-variables.md
index 57b311dbe65b8..3f52d6e032899 100644
--- a/system-variables.md
+++ b/system-variables.md
@@ -285,9 +285,13 @@ Constraint checking is always performed in place for pessimistic transactions (d
 
 ### tidb_enable_cascades_planner
 
+> **Warning:**
+>
+> Currently, cascades planner is an experimental feature. It is not recommended that you use it in the production environment.
+
 - Scope: SESSION | GLOBAL
-- Default value: 0
-- This variable is used to control whether to enable the cascades planner, which is currently considered experimental.
+- Default value: `OFF`
+- This variable is used to control whether to enable the cascades planner.
 
 ### tidb_enable_chunk_rpc <span class="version-mark">New in v4.0</span>
 
@@ -297,6 +301,10 @@ Constraint checking is always performed in place for pessimistic transactions (d
 
 ### tidb_enable_fast_analyze
 
+> **Warning:**
+>
+> Currently, `Fast Analyze` is an experimental feature. It is not recommended that you use it in the production environment.
+
 - Scope: SESSION | GLOBAL
 - Default value: 0, indicating not enabling the statistics fast `Analyze` feature.
 - This variable is used to set whether to enable the statistics `Fast Analyze` feature.