The present invention relates to a single-chip light-emitting diode (LED) with three luminescent spectrums of red, blue and green wavelengths. The single-chip light-emitting diode of the invention comprises a base, two conductive pins, a single-chip light-emitting element, a package material, and red fluorescent powder. The single-chip light-emitting element is disposed on the base and electrically connected to the two conductive pins. The red fluorescent powder is added to the package material. The single-chip light-emitting element comprises a substrate, an N-type cladding layer, a P-type cladding layer, at least one green light-emitting layer, and at least one blue light-emitting layer. The green light-emitting and blue light-emitting layers are formed between the N-type cladding layer and the P-type cladding layer. According to the single-chip LED of the present invention, the green and blue light spectrums are direct light sources respectively supplied for the blue light-emitting layer and the green light-emitting layer of the single-chip light-emitting element. The red light spectrum is a red light generated by exciting the red fluorescent powder with the blue or green light or their combination of the single-chip light-emitting element. Therefore, the single-chip LED with the three luminescent spectrums of red, blue and green wavelengths may be applied to the backlight source of the liquid crystal display module to provide the properties of high color-rendering, preferred power-saving and small volume.