A frame of a backlight module includes a first side bar, a second side bar, a third side bar and a fourth side bar. The first side bar, the second side bar, the third side bar and the fourth side bar are connected end to end. The frame includes two contacting portions. One of the contacting portions is positioned at a corner of the first side bar and the second side bar, and the other one of the contacting portions is positioned at another corner of the first side bar and the fourth side bar.