diff --git a/Optimization.md b/Optimization.md
index 25ae8e9..ee23029 100644
--- a/Optimization.md
+++ b/Optimization.md
@@ -142,7 +142,7 @@ By default, if there is a slow read request caused by network problems, this req
 
 Set `volume.hasSlowRead` to true,this prevents slow reads from blocking other requests,but large file read P99 latency will increase.
 
-Increasing `volume.readBufferSize` (for example, set to `filer.maxMB` size) can make read requests require fewer locks , which can fix the P99 latency problem caused by `volume.hasSlowRead`
+Increasing `volume.readBufferSizeMB` (for example, set to `filer.maxMB` size) can make read requests require fewer locks , which can fix the P99 latency problem caused by `volume.hasSlowRead`
 
 ## Logging