The present invention discloses a backlight module which includes a waveguide and a spot light source. Wherein the waveguide includes an incident face and a refractive surface adjacent to the waveguide, the light beam emitted from the spot light source will be directed toward the refractive surface, and then the light beam enters the waveguide after the light beam is refracted by the refractive surface. The present invention also discloses a liquid crystal display device incorporated with the backlight module disclosed. The backlight module can readily improve the corner vignette and enhanced with more evenly distributed brightness across the waveguide. The liquid crystal display device incorporated with the module also enjoy the evenly distributed brightness.