PURPOSE:To investigate the cause and treatment of iatrogenic retinal breaks(lRB)in microvitreoretinal surgery. METHODS:The causes and treatments of 40 iatrogenie retinal breaks of 24 cases in micro-vitreoretinal surgery from July1994 to March 1996 in our department were analyzed retrospectively. RESULTS:40 IRB were found in 24 eyes,among them there were 16 eyes of proliferative vitreoretinopathy(PVR),5 eyes of taumatic PVR and 3 eyes of tractional retinal detachment, The treatments of IRB included scleral cryotherapy ,silicone band buckling,endodiathermy,intraocular tamponade and postoperative argon laser. The IRB of inferior retina and posterior Io scleral buckling acounded for 70% and 92% respectively. The total retinal and macular attachment were 17 eyes and the visual acuity of 19 eyes improved to 0.02 or better during the mean follow up periods of 5 months. CONCLUSION:The IRB is a severe complication in micro-vitrecretinal surgery and has to be obliterated either intraoperatively or postoperatively. （Chin J Ocul Fundus Dis,1997,13: 19-21 ）