AIM:To observe clinical effects of intravitreous injection of avastin(bevacizumab) in central retinal vein occlusion (CRVO) with macular edema(ME). METHODS:Indirect ophthalmoscopy,optical coherence tomography(OCT) and fundus fluorescein angiography (FFA) confirmed that 72 patients 75 eyes had CRVO with ME in our hospital from April 2007 to October 2009.Group A had 38 patients 39 eyes,group A1 of 20 patients 21 eyes received intravitreal injection of 1.25mg(0.05mL) avastin, group A2 of 18 patients with 18 eyes received intravitreal injection of 1.25mg(0.05mL) avastin and the treatment was repeated after 4 weeks.Group B had 34 patients 36 eyes,group B1 of 16 patients 16 eyes received intravitreal injection of 2.0mg(0.08mL) avastin,group B2 of 18 patients 20 eyes received intravitreal injection of 2.0mg (0.08mL) avastin and the treatment was repeated after 4 weeks.Visual acuity,intraocular pressure and fundus were compared before each treatment,1 week,2,4 weeks after treatment.The performance of FFA and OCT macular retinal thickness measurement were compared before treatment and 4 weeks after treatment. RESULTS:Out of 72 patients 75 eyes,visual acuity of 58 patients 61 eyes was improved and macular edema reduced.The difference between group A1 and group A2,group B1 and group B2 was significant(P<0.01). There was no statistically significant difference between group A1 and group B1,group A2 and group B2. CONCLUSION:Intravitreal injection of avastin can improve the CRVO in patients with ME secondary to a high degree of visual acuity and ME,repeated treatment effect is more obvious.But the increase intravitreal injection of avastin did not significantly reduce the high degree of ME.