AIM:To evaluate the efficacy and safety of intravitreal avastin for diabetic macular edema(DME)(diabetic retinopathy Ⅳ period and macular edema above metaphase)·METHODS:Totally 60 patients who were diagnosed by fundus fluorescein angiography(FFA) from January 2009 to December 2010 with declining eyesight and diabetes of clinical treatment significance FFA showed diabetic retinopathy in Ⅳ period,optical coherence tomography(OCT) examination showed moderate or above macular edema,macular edema history did not exceed 3 months were selected.All eyes received a baseline eye examination before treatment,which included intraocular pressure,slit-lamp,best-corrected visual acuity,mydriatic fundus examination,and color retinal photography,FFA,OCT were performed.An intravitreal injection of avastin(1.25mg) was given at baseline and followed by two additional injections of four weeks intervals.Recording the first day,the second day,the third day,the third week,the third month,the sixth month of best-corrected visual acuity,intraocular pressure,the change of lens and vitreous,status of retinal leakage and observing postoperative central retinal thickness by OCT to compare·RESULTS:The intravitreous injection of avastin could improve vision function and decrease central macular thickness(CMT) obviously.The central macular thickness was(395.933±119.784)μm in preinjection and(314.200±60.528)μm in postinjection,showing a statistically significant difference between them.During the follow-up,no significant changes in intraocular pressure and cataract were observed.The retina toxicity reaction relevant to avastin and local or systemic adverse reactions were nothing·CONCLUSION:The intravitreous injection of avastin can relieve macular edema and improve visual acuity stably for diabetic retinopathy patients.However,its long-term treatment effect requires a large sample of experiments to further confirm.