diff --git a/fe/fe-core/src/main/java/com/starrocks/sql/optimizer/cost/CostModel.java b/fe/fe-core/src/main/java/com/starrocks/sql/optimizer/cost/CostModel.java
index f211c4b3ecb8a7..a3ffa7f88bebbe 100644
--- a/fe/fe-core/src/main/java/com/starrocks/sql/optimizer/cost/CostModel.java
+++ b/fe/fe-core/src/main/java/com/starrocks/sql/optimizer/cost/CostModel.java
@@ -175,11 +175,7 @@ public CostEstimate visitPhysicalOlapScan(PhysicalOlapScanOperator node, Express
                 }
             }
 
-            // ScanOperator use a ChunkBuffer to implement async-io, which may takes significant memory for certain
-            // cases
-            SessionVariable variables = ConnectContext.get().getSessionVariable();
-            double memCost = (double) statistics.getAvgRowSize() * variables.getDegreeOfParallelism();
-            return CostEstimate.of(statistics.getComputeSize(), memCost, 0);
+            return CostEstimate.of(statistics.getComputeSize(), 0, 0);
         }
 
         @Override
diff --git a/fe/fe-core/src/test/java/com/starrocks/sql/plan/PlanFragmentWithCostTest.java b/fe/fe-core/src/test/java/com/starrocks/sql/plan/PlanFragmentWithCostTest.java
index f0e1732adce70a..dd08aa9b2aa307 100644
--- a/fe/fe-core/src/test/java/com/starrocks/sql/plan/PlanFragmentWithCostTest.java
+++ b/fe/fe-core/src/test/java/com/starrocks/sql/plan/PlanFragmentWithCostTest.java
@@ -2237,11 +2237,11 @@ public void testPlanCost() throws Exception {
             System.out.println(plan);
             assertContains(plan, "PLAN COST\n" +
                     "  CPU: 4.80001312001E11\n" +
-                    "  Memory: 320241.0");
+                    "  Memory: 320201.0");
 
             assertContains(getCostExplain(sql), "PLAN COST\n" +
                     "  CPU: 4.80001312001E11\n" +
-                    "  Memory: 320241.0");
+                    "  Memory: 320201.0");
 
             AuditEvent event = connectContext.getAuditEventBuilder().build();
             Assert.assertTrue("planMemCosts should be > 1, but: " + event.planMemCosts, event.planMemCosts > 1);
diff --git a/fe/fe-core/src/test/java/com/starrocks/sql/plan/ReplayFromDumpTest.java b/fe/fe-core/src/test/java/com/starrocks/sql/plan/ReplayFromDumpTest.java
index 8cdf5c90a858c9..b26cce619a3465 100644
--- a/fe/fe-core/src/test/java/com/starrocks/sql/plan/ReplayFromDumpTest.java
+++ b/fe/fe-core/src/test/java/com/starrocks/sql/plan/ReplayFromDumpTest.java
@@ -509,7 +509,7 @@ public void testMultiSubqueries() throws Exception {
     public void testCorrelatedPredicateRewrite() throws Exception {
         Pair<QueryDumpInfo, String> replayPair =
                 getPlanFragment(getDumpInfoFromFile("query_dump/union_with_subquery"), null, TExplainLevel.COSTS);
-        Assert.assertTrue(replayPair.second, replayPair.second.contains("1197:HASH JOIN\n" +
+        Assert.assertTrue(replayPair.second, replayPair.second.contains("1201:HASH JOIN\n" +
                 "  |  join op: RIGHT OUTER JOIN (BUCKET_SHUFFLE(S))\n" +
                 "  |  equal join conjunct: [3802: ref_id, BIGINT, true] = [3681: customer_id, BIGINT, true]"));
     }