This tutorial is for all those who are already using Custom Domains with Blogger. If you already have a blogger blog at some Custom domain like www.yourdomain.com , then you might want to add a sub domains to this custom domain like blog.yourdomain.com gallery.yourdomain.com etc. An example of such a sub-domain is blog.achrafpro.com It is a blogger powered blog, which i created on the sub-domain. In order to create blogs at sub-domains, you need to create CNAME records for the same.

Create Sub Domain on a Blogger Custom Domain

Here we will learn how we can add a new sub domain to your blogger custom domain blog. As an example we will learn how to create a sub domain blog.yourdomain.com to your custom domain blog. (If you have need some other sub-domain change blog with what you want). To do that we need to create a CNAME record.
1. blog.yourdomain.com pointing to ghs.google.com
If you are having a self hosted website, then you will have to create this CNAME Record with your Web Host.You might be able to do it from the “Simple DNS Zone Editor” in most cPanels. If you don’t have such an option, contact your Web Host and ask them to create these two CNAME records for you.After creating this record with your webhost(and after it has propagated), Skip the tutorials for CNAME Creation on Different domain Registrars. They are not applicable for Self hosted Websites
If you don’t have a self hosted  website,then to create the CNAME you need to login to your domain control panel. Different Registrars have different interfaces(we have listed 4 of them here) but the basic thing is that you need to create the CNAME Record. If you bought the domain via blogger, then you have to first login to Google APPS to get into your Domain Control panel

If you bought the domain from Blogger

If you bought the domain from within Blogger, then you have to get into your domain control panel. To do that go to
http://google.com/a/cpanel/yourdomain.com
you will have to replace yourdomain.com with your domain name. From the Google APPS dashboard, Go to Domain Settings > Domain Names and click on Advanced DNS Settings. From the new page, Sign in to DNS Console(of Enom or Godaddy with the username and password that you get from here.)

Switching your BlogSpot blog to the Custom Sub-Domain

I assume that you have already have a blog which you want to switch to the custom-sub domain. Get into its Dashboard and navigate to Settings > Add Custom Domain and click on the link saying “Already own a domain? Switch to advanced settings” Now provide the URL blog.yourdomain.com . Type the captcha and save the Settings.





Done.