An LED, a backlight module, and a liquid crystal display device. The LED (100) comprises a support frame (1), a light-emitting chip (2), and a light conversion layer, where the support frame is provided with an upwardly opened cavity, the light-emitting chip is arranged within the cavity of the support frame and is mounted at the bottom wall of the support frame, the wavelength of a light emitted by the light-emitting chip is shorter than that of blue light, the light conversion layer is packaged within the cavity of the support frame, the light conversion layer comprises quantum particles and a packaging adhesive layer (6), the quantum particles comprise red quantum particles (3), green quantum particles (4), and blue quantum particles (5), and the packaging adhesive layer is provided as packaging the red quantum particles, the green quantum particles, and the blue quantum particles. By activating the red, green, and blue quantum particles with the light of which the wavelength is shorter than that of the blue light, the backlight module comprising the LED and the liquid crystal display device are allowed to achieve high color gamut effects and, at the same time, the light conversion efficiency of the quantum particles is increased.