The present invention discloses a LED backlight module and a LCD device using the same, and the backlight module comprises a backplane and a light guide plate, wherein the edge of said light guide plate is fixed on the backplane by elastic part(s). Because the present invention uses the elastic parts to connect the light guide plate with the backplane, uses the elasticity of the elastic parts to fix the light guide plate in the backlight cavity and align the light guide plate with the LED. Thus, the thinner rubber frame designed for thinning is not used for compressing the light guide plate any longer, the backlight module is thinner, and the positioning of the light guide plate is more reliable.