If you want to Embed any YouTube url into ASP.NET page, please got thought the below article. Here I have explained how to play youtube video in Asp net application using youtube video url.

Please create a sample Web Page with a Literal control (ID="youtubeVideo") as shown below : 

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="PlayYouTubeVideo.aspx.cs" Inherits="PlayYouTubeVideo" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
   <head runat="server">
      <title>Play YouTube Video : Hima Sagar Kutikuppala</title>
   </head>
   <body>
      <form id="myform" runat="server">
         <div>
            <h3>Play YouTube Video</h3>
            <br />
            <asp:literal ID="youtubeVideo" runat="server"></asp:literal>
         </div>
      </form>
   </body>
</html>

Please find below the code behind code:

using System;

/// <summary>
/// Play YouTube Video
/// Author : Himasagar Kutikuppala  ( www.himasagar.com )
/// </summary>
public partial class PlayYouTubeVideo : System.Web.UI.Page
{
    /// <summary>
    /// Handles the Load event of the Page control.
    /// </summary>
    /// <param name="sender">The source of the event.</param>
    /// <param name="e">The <see cref="EventArgs"/> instance containing the event data.</param>
    protected void Page_Load(object sender, EventArgs e)
    {
        string source = @"<object width='500' height='300'> ";
        source = source + @"<param name='movie' value='http://www.youtube.com/v/gWtL24IEpy0'></param> ";
        source = source + @"<param name='allowFullScreen' value='true'></param> ";
        source = source + @"<param name='allowscriptaccess' value='always'></param> ";
        source = source + @"<embed src='http://www.youtube.com/v/gWtL24IEpy0'";
        source = source + @"type='application/x-shockwave-flash' allowscriptaccess='always' ";
        source = source + @"allowfullscreen='true' width='500' height='300'> ";
        source = source + @"</embed></object>";

        youtubeVideo.Text = source;
    }
}

Demo:

Play YouTube Video