diff --git a/manager/src/main/resources/define/app-tomcat.yml b/manager/src/main/resources/define/app-tomcat.yml
index 71d1e3d672a..fed04885965 100644
--- a/manager/src/main/resources/define/app-tomcat.yml
+++ b/manager/src/main/resources/define/app-tomcat.yml
@@ -178,12 +178,16 @@ metrics:
         instance: true
       - field: committed
         type: 0
+        unit: MB
       - field: init
         type: 0
+        unit: MB
       - field: max
         type: 0
+        unit: MB
       - field: used
         type: 0
+        unit: MB
     # (optional)metrics field alias name, it is used as an alias field to map and convert the collected data and metrics field
     # (可选)监控指标别名, 做为中间字段与采集数据字段和指标字段映射转换
     aliasFields:
@@ -192,6 +196,11 @@ metrics:
       - Usage->init
       - Usage->max
       - Usage->used
+    units:
+      - committed=B->MB
+      - init=B->MB
+      - max=B->MB
+      - used=B->MB
     # mapping and conversion expressions, use these and aliasField above to calculate metrics value
     # (可选)指标映射转换计算表达式,与上面的别名一起作用,计算出最终需要的指标值
     # eg: cores=core1+core2, usage=usage, waitTime=allTime-runningTime