A liquid crystal display and a backlight module thereof are provided. The backlight module includes a backlight source and a light guide plate. The backlight source is disposed at a side surface of the light guide plate. The light guide plate has an accommodation section for accommodating a functional module. The backlight module includes a compensation light source that is disposed on the light guide plate. The accommodation section is located between the backlight source and the compensation light source. The backlight module includes a compensation light source, and the backlight source and the compensation light source are located at two opposite sides of the accommodation section. The compensation light source may compensate for the illumination light in the light guide plate blocked by the functional module, so as to solve the non-uniform display problem of blocking the illumination light from the backlight source by the functional module.