In this section, you create a parent master page. This page contains a banner and navigation controls that can be used throughout the site. Later, you will create another master page that will be used inside this parent master page. Child master pages can provide various layouts for pages while retaining the look that is established by the parent master page.
To create the master page

1.In Solution Explorer, right-click the name of the Web site, and then click Add New Item.
The Add New Item dialog box is displayed.
2. Under Visual Studio installed templates, click Master Page.
3. In the Name box, type ParentMaster.
4. Clear the Place code in separate file check box.
5. In the Language list, click the programming language that you prefer to work with.
6. Click Add.

The new master page is opened in Source view.
And this example also we can creating a Master Pages in ASP.NET
<%@ Master Language="VB" CodeFile="otc.master.vb" Inherits="otc" %>



<html xmlns="">

<head runat="server">

<title>Untitled Page</title>

<link href="~/StyleSheet.css" rel="Stylesheet" type="text/css" />



<form id="form1" runat="server">

<asp:Menu ID="Menu1" runat="server" Orientation="Horizontal">


<asp:MenuItem NavigateUrl="~/Default.aspx" Text="Home" Value="Home"/>

<asp:MenuItem NavigateUrl="~/Experiments.aspx"

Text="Experiments" Value="Experiments"/>




<div id="main">

<asp:ContentPlaceHolder ID="mainContent" runat="server" />


<div id="right">

<asp:ContentPlaceHolder ID="sideContent" runat="server" />


<div id="footer">

<asp:Literal ID="Footer" runat="server" Text="" />