A light emitting device array including a circuit substrate and a plurality of device layers is provided. The circuit substrate includes a plurality of bonding pads and a plurality of conductive bumps located over the bonding pads. The device layers are capable of emitting different colored lights electrically connected with the circuit substrate through the conductive bumps and the bonding pads. The device layers capable of emitting different colored lights have different thicknesses and the conductive bumps bonded with the device layers capable of emitting different colored lights have different heights such that top surfaces of the device layers capable of emitting different colored lights are located on a same level of height.