A light emitting diode system includes a first light emitting diode apparatus and a second light emitting diode apparatus. The first light emitting diode apparatus includes an alternating-current-to-direct-current and light-controlling unit, a plurality of first light emitting diode modules and a first connector. The second light emitting diode apparatus includes a second connector, a signal-converting unit and a plurality of second light emitting diode modules. The first light emitting diode apparatus outputs a drive direct current power and a light-controlling signal to the signal-converting unit through the first connector and the second connector. Therefore, the signal-converting unit is configured to control colors and intensities of the second light emitting diode modules.