diff --git a/src/org/ntlab/deltaViewer/CollaborationViewer.java b/src/org/ntlab/deltaViewer/CollaborationViewer.java
index 2cfe039..d23bfc6 100644
--- a/src/org/ntlab/deltaViewer/CollaborationViewer.java
+++ b/src/org/ntlab/deltaViewer/CollaborationViewer.java
@@ -541,7 +541,7 @@
 			}
 			
 			
-			if (srcClassName != null && fieldName != null && !edgeMap.containsKey(srcClassName + "." + fieldName)) {
+			if (srcClassName != null && fieldName != null && !edgeMap.containsKey(curAliasObjId + "." + fieldName)) {
 				// Judge AliasList contains relatedPoint. (If contains not to create edge.)
 				if (rpIndex < relatedPoints.size() - 1) {
 					TracePoint rp = relatedPoints.get(rpIndex);
@@ -569,7 +569,9 @@
 						Point2D absPtSrcCell = getAbsolutePointforCell((mxICell)srcCell);
 						Point2D absPtDstCell = getAbsolutePointforCell((mxICell)dstCell);
 						setEdgePoint((mxICell)edge, absPtSrcCell, absPtDstCell);
-						edgeMap.put(srcClassName + "." + fieldName, new Edge(fieldName, TypeName.Reference, edge));
+						edgeMap.put(curAliasObjId + "." + fieldName, new Edge(fieldName, TypeName.Reference, edge));
+					} else {
+						edgeMap.put(curAliasObjId + "." + fieldName, new Edge(fieldName, TypeName.PreReference, curAliasObjId, nextAliasObjId));
 					}
 				} finally {
 					mxgraph.getModel().endUpdate();
diff --git a/src/org/ntlab/deltaViewer/DeltaViewer.java b/src/org/ntlab/deltaViewer/DeltaViewer.java
index 7a96622..5087049 100644
--- a/src/org/ntlab/deltaViewer/DeltaViewer.java
+++ b/src/org/ntlab/deltaViewer/DeltaViewer.java
@@ -585,7 +585,7 @@
 					System.out.println("ARRAY " + srcClassName + "(" + curAlias.getObjectId() + ") -> " + "(" +  nextAlias.getObjectId() + "),  " + fieldName);
 				}
 			}
-			if (srcClassName != null && fieldName != null && srcClassName != null && !edgeMap.containsKey(srcClassName + "." + fieldName)) {
+			if (srcClassName != null && fieldName != null && srcClassName != null && !edgeMap.containsKey(curAlias.getObjectId() + "." + fieldName)) {
 				// Add a vertex to the graph in a transactional fashion. The vertex is actually a 'cell' in jgraphx terminology.
 				mxgraph.getModel().beginUpdate();
 				try {
@@ -598,7 +598,7 @@
 						Point2D absPtSrcCell = getAbsolutePointforCell((mxICell)srcCell);
 						Point2D absPtDstCell = getAbsolutePointforCell((mxICell)dstCell);
 						setEdgePoint((mxICell)edge, absPtSrcCell, absPtDstCell);
-						edgeMap.put(srcClassName + "." + fieldName, new Edge(fieldName, TypeName.Reference, edge));
+						edgeMap.put(curAlias.getObjectId() + "." + fieldName, new Edge(fieldName, TypeName.Reference, edge));
 					}
 				} finally {
 					mxgraph.getModel().endUpdate();
diff --git a/src/org/ntlab/deltaViewer/Edge.java b/src/org/ntlab/deltaViewer/Edge.java
index bcc3c95..8d343a0 100644
--- a/src/org/ntlab/deltaViewer/Edge.java
+++ b/src/org/ntlab/deltaViewer/Edge.java
@@ -8,9 +8,12 @@
 public class Edge {
 	String label;
 	TypeName typeName;
-	Object cell;
+	Object cell;			// edge cell
+	String srcObjId;	// source object id to create the edge later
+	String dstObjId;	// destination object id to create the edge later
 	
 	protected enum TypeName {
+		PreReference,	// object will be referred later
 		Reference, // object reference
 		Create, // create object reference
 		Call // method call
@@ -26,6 +29,13 @@
 		this.typeName = typeName;
 		this.cell = cell;
 	}
+	
+	public Edge(String label, TypeName typeName, String srcObjId, String dstObjId) {
+		this.label = label;
+		this.typeName = typeName;
+		this.srcObjId = srcObjId;
+		this.dstObjId = dstObjId;
+	}
 
 	public String getLabel() {
 		return label;
@@ -51,4 +61,19 @@
 		this.cell = cell;
 	}
 
+	public String getSrcObjeId() {
+		return srcObjId;
+	}
+
+	public void setSrcObjId(String srcObjId) {
+		this.srcObjId = srcObjId;
+	}
+
+	public String getDstObjeId() {
+		return dstObjId;
+	}
+
+	public void setDstObjeId(String dstObjId) {
+		this.dstObjId = dstObjId;
+	}
 }
diff --git a/src/org/ntlab/deltaViewer/MagnetRONViewer.java b/src/org/ntlab/deltaViewer/MagnetRONViewer.java
index 81e5760..d7e7094 100644
--- a/src/org/ntlab/deltaViewer/MagnetRONViewer.java
+++ b/src/org/ntlab/deltaViewer/MagnetRONViewer.java
@@ -269,7 +269,25 @@
 								"fillColor=white");
 				objectVertex.setCell(ovCell);
 				mxICell edge = (mxICell) mxgraph.insertDeltaEdge(getMxDefaultParent(), fieldName, null, srcCell, ovCell);
-				edgeMap.put(methodExec.getThisClassName() + "." + fieldName, new Edge(fieldName, TypeName.Create, edge));
+				edgeMap.put(alias.getObjectId() + "." + fieldName, new Edge(fieldName, TypeName.Create, edge));
+				for (String edgeKey: edgeMap.keySet()) {
+					Edge e = edgeMap.get(edgeKey);
+					if (edgeKey.startsWith(alias.getObjectId()  + ".") && e.getTypeName() == Edge.TypeName.PreReference) {
+						mxICell dstCell =  (mxICell) objectToVertexMap.get(e.getDstObjeId()).getCell();
+						String fieldNames[] = edgeKey.split(".");
+						mxICell edge2 = null;
+						if (fieldNames.length < 2) {
+							edge2 = (mxICell) mxgraph.insertDeltaEdge(getMxDefaultParent(), "", "", ovCell, dstCell);
+						} else {
+							edge2 = (mxICell) mxgraph.insertDeltaEdge(getMxDefaultParent(), fieldNames[1], fieldNames[1], ovCell, dstCell);
+						}
+						Point2D absPtSrcCell = getAbsolutePointforCell((mxICell)ovCell);
+						Point2D absPtDstCell = getAbsolutePointforCell((mxICell)dstCell);
+						setEdgePoint((mxICell)edge2, absPtSrcCell, absPtDstCell);
+						e.setTypeName(Edge.TypeName.Reference);
+						e.setCell(edge2);
+					}
+				}
 				update();
 			} finally {
 				mxgraph.getModel().endUpdate();
@@ -321,7 +339,25 @@
 								"fillColor=white");
 				objectVertex.setCell(ovCell);
 				mxICell edge = (mxICell) mxgraph.insertDeltaEdge(getMxDefaultParent(), fieldName, null, srcCell, ovCell);
-				edgeMap.put(methodExec.getThisClassName() + "." + fieldName, new Edge(fieldName, TypeName.Create, edge));
+				edgeMap.put(alias.getObjectId() + "." + fieldName, new Edge(fieldName, TypeName.Create, edge));
+				for (String edgeKey: edgeMap.keySet()) {
+					Edge e = edgeMap.get(edgeKey);
+					if (edgeKey.startsWith(alias.getObjectId()  + ".") && e.getTypeName() == Edge.TypeName.PreReference) {
+						mxICell dstCell =  (mxICell) objectToVertexMap.get(e.getDstObjeId()).getCell();
+						String fieldNames[] = edgeKey.split(".");
+						mxICell edge2 = null;
+						if (fieldNames.length < 2) {
+							edge2 = (mxICell) mxgraph.insertDeltaEdge(getMxDefaultParent(), "", "", ovCell, dstCell);
+						} else {
+							edge2 = (mxICell) mxgraph.insertDeltaEdge(getMxDefaultParent(), fieldNames[1], fieldNames[1], ovCell, dstCell);
+						}
+						Point2D absPtSrcCell = getAbsolutePointforCell((mxICell)ovCell);
+						Point2D absPtDstCell = getAbsolutePointforCell((mxICell)dstCell);
+						setEdgePoint((mxICell)edge2, absPtSrcCell, absPtDstCell);
+						e.setTypeName(Edge.TypeName.Reference);
+						e.setCell(edge2);
+					}
+				}
 				update();
 			} finally {
 				mxgraph.getModel().endUpdate();
@@ -368,7 +404,7 @@
 								srcCell, dstCell);
 				edge.setStyle("strokeColor=red;");
 //				mxgraph.orderCells(true, new Object[] {edge});
-				edgeMap.put(fieldUpdateStatement.getFieldName(), new Edge(fieldName, TypeName.Reference, edge));
+				edgeMap.put(fieldUpdateStatement.getContainerObjId(), new Edge(fieldName, TypeName.Reference, edge));
 			} finally {
 				mxgraph.getModel().endUpdate();
 			}