We report successful growth of high-quality InGaAs/InP double quantum wells (DQWs) with safer and more cost-effective decomposition source molecular beam epitaxy (MBE). The transmission electron microscopy (TEM) images and double crystal X-ray diffraction (TCXD) measurement reveal the formation of abrupt interfaces between InGaAs and InP layers. In the case of optical quality, the line width of 12 K-photoluminescence of the DQWs is 8.2 meV, which is comparable to that of single quantum well grown by MBE with PH 3 cracker and more complex instrument (∼4 meV).