A liquid crystal display includes a backlight module that includes a waveguide, a backboard, and a light source. The waveguide is disposed onto the backboard. The light source is arranged adjacent to a light incident surface of the waveguide. The backlight module includes a limiter securely attached to the backboard and abuts the light source so as to ensure a preset distance between the light source and the incident surface of the waveguide. With the limiter of the backlight module arranged to abut the light source, the coupling distance between the light source and the incident surface of the waveguide can be effectively kept constant without being compromised to zero (0) as resulting from expansion under heat or moisture or the accuracy during installation.