Lost in google serp
 

One of my website was first page on google for the keyword but recently it lost its position. What I noticed was one of my competitors site that was on the third page replaces my site. But the other sites are usually be in the same positions as before. Any reasons?

May be Google has put your website in its sandbox due to spamming. Check if you build some bad backlinks for your website in past one month. If you found it then fix them asap.

Thanks a lot.

Check your site backlinks, may be Google pushed backwards your website.