 <p>Try to change your classes like this:</p> <pre><code>class root { public root() { } public studentinfo studentinfo { get; set; } } class studentinfo { public studentinfo() { subject = new List&lt;subject&gt;(); } public string name { get; set; } public int age { get; set; } public string gender { get; set; } public address address; public List&lt;subject&gt; subject; } class address { public string street { get; set; } public string city { get; set; } public string state { get; set; } } class subject { public string name { get; set; } public int marks { get; set; } public string grade { get; set; } } </code></pre> <p>and there's an error with your JSON</p> <pre><code>'gender':male, </code></pre> <p>should be</p> <pre><code> 'gender': 'male', </code></pre>