Objective To expolre the factors which affect the size of diabetic,macular fobeal avascss scular zone(FAZ). Methods Making ten years of duration of diabetes a limit,79 nonproliferative and early proliferative diabetic patients were divided into 2 groups.Diabetic retinopathy severity level was diveided into 4 stages,and the macular edema was subdivided into focal、diffuse and cystoid according to fluorescein leakage of foveomacular region.All patients were measured FAZ with Heidelberg scanning laser fluoresceion angiography system and then compaired the size of FAZ of patients with different duration of diabetes、diabetic retinopathy severity level and macular edema status.The results were performed analysis of variance and t test. ResultsThe study shown the size of FAZ was not directly related to the duration of diabetes(t=1.3854,Pgt;0.1);There were significant differences about the size of FAZ of patients with different diabetic retinopathy severity level(F=7.6251,P＜0.01)and macular edema status(F=5.4369,P＜0.01)． Conclusion The size of FAZ was significantly increased in diabetic patients.It was enlarged with the development of diabetic retinopathy severity level,but it was not related to duration of diabetes. (Chin J Ocul Fundus Dis,2000,16:155-156)