Facebook has a feature, when you add someone as a friend, it is being shown to everyone in your list.However, it doesn’t tell you when someone removes you from his/her friend list. Earlier there was an application named “Unfriender”, which use to do the job of notifying you when someone removes you from his/her friend list. Facebook seems to have banned “Unfriender” application.
There is another new application which let you know when someone removes you from his/her friend list.Application name is “Unfriend Detector”. You may install it from this url.Additionally, you may choose to get notified by an email when someone “unfriend” you. However, it won’t tell you about the friends who have removed you their list before you installed this application.It only works if someone removes you from his/her list after application is installed.