diff --git a/qilin.core/src/qilin/core/builder/FakeMainFactory.java b/qilin.core/src/qilin/core/builder/FakeMainFactory.java
index 669201c..5334c6e 100644
--- a/qilin.core/src/qilin/core/builder/FakeMainFactory.java
+++ b/qilin.core/src/qilin/core/builder/FakeMainFactory.java
@@ -29,8 +29,6 @@
 import java.util.List;
 
 public class FakeMainFactory extends ArtificialMethod {
-    public static FakeMainFactory instance;
-
     public static int implicitCallEdges;
     private final SootClass fakeClass;
 
diff --git a/qilin.pta/src/driver/Main.java b/qilin.pta/src/driver/Main.java
index 73f0282..c36b67d 100644
--- a/qilin.pta/src/driver/Main.java
+++ b/qilin.pta/src/driver/Main.java
@@ -47,10 +47,6 @@ public static PTA run(String[] args) {
             PTAUtils.dumpJimple(jimplePath);
             System.out.println("Jimple files have been dumped to: " + jimplePath);
         }
-        logger.info("Constructing the callgraph...");
-        PackManager.v().getPack("cg").apply();
-        CallGraph cg = PTAScene.v().getCallGraph();
-        System.out.println("#CALLGRAPH:" + cg.size());
         pta = PTAFactory.createPTA(PTAConfig.v().getPtaConfig().ptaPattern);
         pta.run();
         return pta;