At present Matched content is available only for blogs with multiple pages and high volumes of traffic. You can easily find out if your blog is eligible for Matched content by checking the “My sites” section in your AdSense account.
Jut follow these steps to check the eligibility of your blog:
First you need to Sign in to your AdSense account.
Then click the gear icon and then select Settings.
At the sidebar, select My sites.
Then under “My sites“, click Matched content.
In the “Sites” section, check to see if your blog is listed.
If your blog is listed, you can surely place Matched content units on any of its pages.
If your blog isn’t listed, then it’s not currently eligible for Matched content.