Would you like to know who deleted or removed you from their Facebook friend list? well, there is no native way to do that.
But there are apps and extensions that keep track on your friend list and notify you when someone unfriends you.
Who Deleted Me
who.deleted.me is an app to keep track of friends. This is an online app, and will save your friends information on their server instead of your machine. You will receive email alerts when someone unfriends you. The app requires permission to access your public profile. If you are uncomfortable to share, then just stay away from who.deleted.me
Unfriend Notify [No Longer Available]
Its Seems Unfriend Notify has been discontinued
Unfriend Notify for Facebook, is an extension available for Chrome and Firefox. The Chrome extension has got more than 100 thousand users and a decent 4 star rating. Once installed, just go to your Friends page, where you’ll see a new tab section for “Lost Friends”. The extension stores data offline, therefore you don’t have to worry about sharing your information with third party apps.
Note: Be cautious while using Facebook Apps