Facebook don’t provide any feature that tells you who removed your from friend list but still you can find out by reading this tutorial.
Few Facebook apps offer this feature but they start sending spam messages and wall posts to your friends. The feature we are discussing here is completely different and it works better than all others, you can easily find out who unfriended you on Facebook.
Visit this website - http://who.deleted.me and Login with Facebook. Allow permission. You may set app visibility to “Only Me” so that activity done by this app would be visible only to you.
You will be seeing the above screen telling who removed you from friend list, filter it by day, week and month.