1. Go to the YouTube page for the video you want, then click the Embed button below the player.
2. Click the checkbox next to Include related videos. (In other words, remove the checkmark.)
3. Copy the code in the Embed field, then paste it wherever you need it to go.
Or Just add ?rel=0 at the end .
See below example for demo
http://www.youtube.com/embed/o4e4RWO0odg => This link will show related posts at the end.
http://www.youtube.com/embed/o4e4RWO0odg?rel=0 => This link will not show related posts at the end. .