Objective To observe the therapeutic efficacy of widefi eld digita l pediatric retinal imaging system (RetCam II)assisted photocoagulation on ret in opathy of preamturity (ROP). Methods The clinical data of 30 p atie nts (58 eyes) with threshold ROP or prethreshold type I ROP were retrospectively analyzed. The nonperfusion area underwent semiconducting photocoagulation wit h 532 nm under indirect binocular ophthalmoscope. In 30 patients, prethreshold ty pe 1 ROP was found in 36 and threshold ROP was in 19; missed area after cryotherapy in other hospital was observed in 3; Zone 1 ROP was in 8 and z one 2 ROP was in 50. Fiftyfour eyes (93.1％) underwent onetime photocoagulat i on and 4 eyes (6.9%) underwent a second. Ocular fundus was examined by RetCam II before and after operation. The missed area after cryoth erapy was at once supplemented during surgery. The followup duration was 3－11 m onths (average of 5.5 months). Results Fiftyfour eyes which had under gone onetime photocoagulation had good result 1－3 weeks after surgery and the disease was controlled. In 4 eyes which had undergone t he second photoco agulation, the disease alleviated after the operation in 2 and local posterior t ractional retinal detachment occurred in 2. At the end of followup duration, u n favorable retinal structural outcome was observed in 2 eyes (3.4%). Con clusion R etCam IIassisted photocoagulation can avoid missed area during the operation， enhance successful rates of first photocoagulation and reduce unfavorabl e retinal structural outcome rates.