The present invention relates to a frame structure and a backlight module. The frame structure comprises four subframes, retaining holes arranged on a side of a back plate, and fixing parts; each of the subframes has an inner side formed with at least one retaining part; the corresponding subframe is fixed on the side of the back plate by matching the retaining hole with the corresponding retaining part. The frame structure and the backlight module of the present invention can lower manufacturing cost and enhance the assembly/disassembly efficiency of the frame.