diff --git a/src/onnx.js b/src/onnx.js
index b5134fe304..0a76472b9b 100644
--- a/src/onnx.js
+++ b/src/onnx.js
@@ -136,7 +136,7 @@ onnx.Model = class {
         this._graphs = [];
         if (model && model.graph) {
             var graphMetadata = new onnx.GraphMetadata(metadata, this._opsetImport);
-            var graph = new onnx.Graph(graphMetadata, model.graph, 0, this._imageFormat);
+            var graph = new onnx.Graph(graphMetadata, this._imageFormat, model.graph);
             this._graphs.push(graph);
         }
     }
@@ -223,18 +223,16 @@ onnx.Model = class {
 
 onnx.Graph = class {
 
-    constructor(metadata, graph, index, imageFormat) {
-        this._metadata = metadata;
+    constructor(metadata, imageFormat, graph) {
         this._node = '';
         this._description = '';
         this._nodes = [];
         this._inputs = [];
         this._outputs = [];
         this._operators = {};
-        this._imageFormat = imageFormat;
 
         if (graph) {
-            this._name = graph.name || ('(' + index.toString() + ')');
+            this._name = graph.name || null;
             this._description = graph.doc_string || '';
 
             var initializers = {};
@@ -284,7 +282,7 @@ onnx.Graph = class {
             nodes.forEach((node) => {
                 var inputs = [];
                 if (node.input) {
-                    inputs = this._metadata.getInputs(node.op_type, node.input);
+                    inputs = metadata.getInputs(node.op_type, node.input);
                     inputs = inputs.map((input) => {
                         return new onnx.Argument(input.name, input.connections.map((connection) => {
                             return this._connection(connections, connection.id, null, null, initializers[connection.id]);
@@ -293,14 +291,14 @@ onnx.Graph = class {
                 }
                 var outputs = [];
                 if (node.output) {
-                    outputs = this._metadata.getOutputs(node.op_type, node.output);
+                    outputs = metadata.getOutputs(node.op_type, node.output);
                     outputs = outputs.map((output) => {
                         return new onnx.Argument(output.name, output.connections.map((connection) => {
                             return this._connection(connections, connection.id, null, null, initializers[connection.id]);
                         }));
                     });
                 }
-                this._nodes.push(new onnx.Node(this, node.op_type, node.domain, node.name, node.doc_string, node.attribute, inputs, outputs));
+                this._nodes.push(new onnx.Node(metadata, imageFormat, node.op_type, node.domain, node.name, node.doc_string, node.attribute, inputs, outputs));
             });
         }
     }
@@ -404,8 +402,8 @@ onnx.Connection = class {
 
 onnx.Node = class {
 
-    constructor(graph, operator, domain, name, description, attributes, inputs, outputs) {
-        this._graph = graph;
+    constructor(metadata, imageFormat, operator, domain, name, description, attributes, inputs, outputs) {
+        this._metadata = metadata;
         this._operator = operator;
         if (domain) {
             this._domain = domain;
@@ -419,7 +417,7 @@ onnx.Node = class {
         this._attributes = [];
         if (attributes && attributes.length > 0) {
             attributes.forEach((attribute) => { 
-                this._attributes.push(new onnx.Attribute(this.graph.metadata, this.operator, attribute));
+                this._attributes.push(new onnx.Attribute(this._metadata, imageFormat, this.operator, attribute));
             });
         }            
         this._inputs = inputs;
@@ -443,7 +441,7 @@ onnx.Node = class {
     }
 
     get documentation() {
-        var schema = this._graph.metadata.getSchema(this._operator);
+        var schema = this._metadata.getSchema(this._operator);
         if (schema) {
             var options = { baseUrl: 'https://github.com/onnx/onnx/blob/master/docs/' };
             schema = JSON.parse(JSON.stringify(schema));
@@ -498,7 +496,7 @@ onnx.Node = class {
     }
 
     get category() {
-        var schema = this._graph.metadata.getSchema(this._operator);
+        var schema = this._metadata.getSchema(this._operator);
         return (schema && schema.category) ? schema.category : null;
     }
 
@@ -521,15 +519,11 @@ onnx.Node = class {
     get dependencies() {
         return [];
     }
-
-    get graph() {
-        return this._graph;
-    }
 };
 
 onnx.Attribute = class {
 
-    constructor(metadata, operator, attribute) {
+    constructor(metadata, imageFormat, operator, attribute) {
         this._name = attribute.name;
         this._type = null;
         this._value = null;
@@ -570,7 +564,7 @@ onnx.Attribute = class {
             }
         }
         else if (attribute.graphs && attribute.graphs.length > 0) {
-            this._value = arg.graphs.map((graph) => new onnx.Graph(metadata, graph));
+            this._value = arg.graphs.map((graph) => new onnx.Graph(metadata, imageFormat, graph));
             this._type = 'graph[]';
         }
         else if (attribute.s && attribute.s.length > 0) {
@@ -593,7 +587,7 @@ onnx.Attribute = class {
         }
         else if (attribute.hasOwnProperty('g')) {
             this._type = 'graph';
-            this._value = new onnx.Graph(metadata, attribute.g);
+            this._value = new onnx.Graph(metadata, imageFormat, attribute.g);
         }
 
         var attributeSchema = metadata.getAttributeSchema(operator, attribute.name);