diff --git a/system-variables.md b/system-variables.md
index f0eeb0b9e9dfd..dff4cc5798829 100644
--- a/system-variables.md
+++ b/system-variables.md
@@ -1389,6 +1389,15 @@ mysql> SELECT job_info FROM mysql.analyze_jobs ORDER BY end_time DESC LIMIT 1;
 - This variable is used to control whether to enable the [baseline capturing](/sql-plan-management.md#baseline-capturing) feature. This feature depends on the statement summary, so you need to enable the statement summary before you use baseline capturing.
 - After this feature is enabled, the historical SQL statements in the statement summary are traversed periodically, and bindings are automatically created for SQL statements that appear at least twice.
 
+### tidb_cb_pd_metadata_error_rate_threshold_pct <span class="version-mark">New in v9.0.0</span>
+
+- Scope: GLOBAL
+- Persists to cluster: Yes
+- Applies to hint [SET_VAR](/optimizer-hints.md#set_varvar_namevar_value): No
+- Default value: `0`
+- Range: `[0, 100]`
+- This variable controls whether TiDB triggers the circuit breaker according to the error rate percentage of the specific requests sent to PD.
+
 ### tidb_cdc_write_source <span class="version-mark">New in v6.5.0</span>
 
 > **Note:**