Log in to your AdSense account and generate the HTML code for the AdSense format you want to display under your blog post title
Encode AdSense Code.
If you paste the AdSense code directly into the HTML code of you blogger template, you will get an error message and your AdSense ads will not display properly
Why? Because blogger is in XML and the XML code needs the HTML code characters like <, > and & to be converted to entities for the code to be interpreted.
To convert your AdSense HTML code to a format that will display properly on Blogger you need to use an HTML encoder. then
Log in to your blogger account
In the dashboard click on the 'layout/design' tab
Once the layout has loaded, click on the 'Edit HTML' tab in the navigation
Back up your current template.
This is very important. You are about to edit the template of your blog and if you make a significant mistake you want your blog template available to reload
Click on the 'Expand Widget Templates' radio button.
Find following any one code
<div class='post-body entry-content'>
OR
<p><data:post.body/></p>
OR
<p><data:post.body/></p>
Paste your encoded AdSense code just above
You can preview your results before saving the new template