What is Google Adsense Section targeting? Here is the official information on Adsense Help Center:

• Section targeting allows you to suggest sections of your text and HTML content that you'd like us to emphasize or downplay when matching ads to your site's content. By providing us with your suggestions, you can assist us in improving your ad targeting. We recommend that only those familiar with HTML attempt to implement section targeting.
• To implement section targeting, you'll need to add a set of special HTML comment tags to your code. These tags will mark the beginning and end of whichever section(s) you'd like to emphasize or de-emphasize for ad targeting.
• The HTML tags to emphasize a page section take the following format:

<!-- google_ad_section_start --> YOUR PAGE CONTENT <!-- google_ad_section_end -->

Now, how can you implement Adsense Section Targeting on New Blogger? If you want to get relevant ads, applying Adsense Section Targeting to your blog use above the code before and after post titles and post content.

Follow these steps to do it.

1.Log in to your dashboard--> layout- -> Edit HTML

2.Click on "Expand Widget Templates"

3.Scroll down to where you see this:

<b:includable id='post' var='post'> <div class='post uncustomized-post-template'> <a expr:name='data:post.id'/> <b:if cond='data:post.title'> <h3 class='post-title'> <b:if cond='data:post.link'> <a expr:href='data:post.link'><data:post.title/></a> <b:else/> <b:if cond='data:post.url'> <a expr:href='data:post.url'><data:post.title/></a> <b:else/> <data:post.title/> </b:if> </b:if> </h3> </b:if>

4.Now replace above code with below code.

<b:includable id='post' var='post'> <div class='post uncustomized-post-template'> <a expr:name='data:post.id'/> <b:if cond='data:post.title'> <h3 class='post-title'> <b:if cond='data:post.link'> <a expr:href='data:post.link'><!-- google_ad_section_start --><data:post.title/><!-- google_ad_section_end --></a> <b:else/> <b:if cond='data:post.url'> <a expr:href='data:post.url'><!-- google_ad_section_start --><data:post.title/><!-- google_ad_section_end --></a> <b:else/> <!-- google_ad_section_start --><data:post.title/><!-- google_ad_section_end --> </b:if> </b:if> </h3> </b:if>

5.Now again scroll down to where you see this:

<data:post.body/>

6.Now replace above code with below code.

<!-- google_ad_section_start --><data:post.body/><!-- google_ad_section_end -->

7.Now save your template and you are done. Share