diff --git a/src/org/ntlab/deltaViewer/CollaborationLayout.java b/src/org/ntlab/deltaViewer/CollaborationLayout.java
index 30f331b..45ea389 100644
--- a/src/org/ntlab/deltaViewer/CollaborationLayout.java
+++ b/src/org/ntlab/deltaViewer/CollaborationLayout.java
@@ -151,6 +151,26 @@
 						}					
 					}
 				}
+			} else if (a.getAliasType() == AliasType.FORMAL_PARAMETER) {
+				MethodExecution methodExec = a.getOccurrencePoint().getMethodExecution();
+				if (methodExec.isStatic()) {
+					// For calls to a static method.
+					String dstClassName = methodExec.getThisClassName();
+					String srcClassName = methodExec.getCallerMethodExecution().getThisClassName();
+					String dstObjId = methodExec.getThisObjId() + ":" + dstClassName;
+					String srcObjId = null;
+					if (!methodExec.getCallerMethodExecution().isStatic()) {
+						srcObjId = methodExec.getCallerMethodExecution().getThisObjId();
+					} else {
+						srcObjId = methodExec.getCallerMethodExecution().getThisObjId() + ":" + srcClassName;							
+					}
+					Reference r = new Reference(srcObjId, dstObjId, srcClassName, dstClassName);
+					idx = references.indexOf(r);
+					if (idx < 0) {
+						references.add(r);
+						idx = references.indexOf(r);
+					}					
+				}
 			}
 			if (idx >= 0) {
 				Reference r = references.get(idx);
diff --git a/src/org/ntlab/deltaViewer/CollaborationViewer.java b/src/org/ntlab/deltaViewer/CollaborationViewer.java
index 10fc087..1a7ce0f 100644
--- a/src/org/ntlab/deltaViewer/CollaborationViewer.java
+++ b/src/org/ntlab/deltaViewer/CollaborationViewer.java
@@ -421,6 +421,17 @@
 						mxICell vertex = (mxICell) mxgraph.insertDeltaVertex(getMxDefaultParent(), thisObjId, thisClassName, 0, 0, objecVertexWidth, ObjectVertexHeight, "fillColor=white"); //creates a white vertex. 
 						objectToVertexMap.put(thisObjId, new ObjectVertex(thisClassName, vertex, 0, 0));
 					}
+				} else if (alias.getAliasType() == Alias.AliasType.FORMAL_PARAMETER) {
+					String thisClassName = alias.getMethodExecution().getThisClassName();
+					String thisObjId = alias.getMethodExecution().getThisObjId();
+					if (thisObjId.matches("0")) {
+						thisObjId += ":" + thisClassName;
+					}
+					if (!objectToVertexMap.containsKey(thisObjId)) {
+						// When the called method are static.
+						mxICell vertex = (mxICell) mxgraph.insertDeltaVertex(getMxDefaultParent(), thisObjId, thisClassName, 0, 0, objecVertexWidth, ObjectVertexHeight, "fillColor=white"); //creates a white vertex. 
+						objectToVertexMap.put(thisObjId, new ObjectVertex(thisClassName, vertex, 0, 0));
+					}
 				}
 			}
 		} finally {
diff --git a/src/org/ntlab/deltaViewer/MagnetRONViewer.java b/src/org/ntlab/deltaViewer/MagnetRONViewer.java
index 3c62966..81e5760 100644
--- a/src/org/ntlab/deltaViewer/MagnetRONViewer.java
+++ b/src/org/ntlab/deltaViewer/MagnetRONViewer.java
@@ -915,11 +915,10 @@
 			methodSignature = formatMethodSignature(methodSignature, methodExecution.getThisClassName());
 		}
 
-		// Why is the following code needed?		
-		if (methodExecution.isStatic() && !objectId.startsWith("0")) {
-			objectId = methodExecution.getCallerMethodExecution().getThisObjId();
+		if (methodExecution.isStatic() && !objectId.startsWith("0")) {		// Check the object id is a formal parameter's one.
+			objectId = methodExecution.getThisObjId();
 			if (objectId.matches("0")) {
-				objectId += ":" + methodExecution.getCallerMethodExecution().getThisClassName();
+				objectId += ":" + methodExecution.getThisClassName();
 			}
 		}