diff --git a/CHANGES.md b/CHANGES.md
index c08c944f3..58e48f607 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -50,6 +50,7 @@ Release Notes.
 * Fix tags store of log and trace on h2/mysql/pg storage.
 * Merge indices by Metrics Function and Meter Function in Elasticsearch Storage. 
 * Fix receiver don't need to get itself when healthCheck
+* Remove group concept from AvgHistogramFunction. Heatmap(function result) doesn't support labels.
 
 #### UI
 * Update selector scroller to show in all pages.
diff --git a/oap-server/analyzer/meter-analyzer/src/main/java/org/apache/skywalking/oap/meter/analyzer/MetricConvert.java b/oap-server/analyzer/meter-analyzer/src/main/java/org/apache/skywalking/oap/meter/analyzer/MetricConvert.java
index e87d3e03b..599ef093d 100644
--- a/oap-server/analyzer/meter-analyzer/src/main/java/org/apache/skywalking/oap/meter/analyzer/MetricConvert.java
+++ b/oap-server/analyzer/meter-analyzer/src/main/java/org/apache/skywalking/oap/meter/analyzer/MetricConvert.java
@@ -21,15 +21,14 @@ package org.apache.skywalking.oap.meter.analyzer;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableMap;
 import io.vavr.control.Try;
+import java.util.List;
+import java.util.StringJoiner;
+import java.util.stream.Stream;
 import lombok.extern.slf4j.Slf4j;
 import org.apache.skywalking.oap.meter.analyzer.dsl.SampleFamily;
 import org.apache.skywalking.oap.server.core.analysis.meter.MeterSystem;
 import org.elasticsearch.common.Strings;
 
-import java.util.List;
-import java.util.StringJoiner;
-import java.util.stream.Stream;
-
 import static java.util.stream.Collectors.toList;
 
 /**
@@ -49,9 +48,14 @@ public class MetricConvert {
 
     public MetricConvert(MetricRuleConfig rule, MeterSystem service) {
         Preconditions.checkState(!Strings.isNullOrEmpty(rule.getMetricPrefix()));
-        this.analyzers = rule.getMetricsRules().stream().map(r -> Analyzer.build(formatMetricName(rule, r.getName()),
-                                                                                 Strings.isEmpty(rule.getExpSuffix()) ? r.getExp() : String.format("(%s).%s", r.getExp(), rule.getExpSuffix()), service))
-            .collect(toList());
+        this.analyzers = rule.getMetricsRules().stream().map(
+            r -> Analyzer.build(
+                formatMetricName(rule, r.getName()),
+                Strings.isEmpty(rule.getExpSuffix()) ?
+                    r.getExp() : String.format("(%s).%s", r.getExp(), rule.getExpSuffix()),
+                service
+            )
+        ).collect(toList());
     }
 
     /**
diff --git a/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/meter/function/avg/AvgHistogramFunction.java b/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/meter/function/avg/AvgHistogramFunction.java
index 508dc697f..2fefde8b9 100644
--- a/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/meter/function/avg/AvgHistogramFunction.java
+++ b/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/meter/function/avg/AvgHistogramFunction.java
@@ -18,7 +18,6 @@
 
 package org.apache.skywalking.oap.server.core.analysis.meter.function.avg;
 
-import com.google.common.base.Strings;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Objects;
@@ -86,17 +85,12 @@ public abstract class AvgHistogramFunction extends Metrics implements Acceptable
 
         this.entityId = entity.id();
 
-        String template = "%s";
-        if (!Strings.isNullOrEmpty(value.getGroup())) {
-            template   = value.getGroup() + ":%s";
-        }
         final long[] values = value.getValues();
         for (int i = 0; i < values.length; i++) {
             long bucket = value.getBuckets()[i];
             String bucketName = bucket == Long.MIN_VALUE ? Bucket.INFINITE_NEGATIVE : String.valueOf(bucket);
-            String key = String.format(template, bucketName);
-            summation.valueAccumulation(key, values[i]);
-            count.valueAccumulation(key, 1L);
+            summation.valueAccumulation(bucketName, values[i]);
+            count.valueAccumulation(bucketName, 1L);
         }
     }
 
diff --git a/oap-server/server-core/src/test/java/org/apache/skywalking/oap/server/core/analysis/meter/function/avg/AvgHistogramFunctionTest.java b/oap-server/server-core/src/test/java/org/apache/skywalking/oap/server/core/analysis/meter/function/avg/AvgHistogramFunctionTest.java
index 477d9695e..b5d058801 100644
--- a/oap-server/server-core/src/test/java/org/apache/skywalking/oap/server/core/analysis/meter/function/avg/AvgHistogramFunctionTest.java
+++ b/oap-server/server-core/src/test/java/org/apache/skywalking/oap/server/core/analysis/meter/function/avg/AvgHistogramFunctionTest.java
@@ -240,11 +240,7 @@ public class AvgHistogramFunctionTest {
             1,
             3,
             6,
-            7,
-            2,
-            4,
-            6,
-            8
+            7
         }, results);
     }