A broadcast receiver and a 3D subtitle data processing method thereof are disclosed. A method for processing three dimensional (3D) subtitle data includes receiving, by a receiver, a broadcast signal including 3D subtitle data, extracting, by an extracting unit, subtitle display information for a base view and extended subtitle display information for an extended view from the 3D subtitle data, and controlling, by a controller, a 3D subtitle display using the subtitle display information for the base view and the extended subtitle display information for the extended view.