PURPOSE:To measure the epidermal growth factor (EGF)contents in vitreous and serum samples in normal subjects and patients with proliferative retinal diseases. METHODS: Using radioreceptor assay(RRA)to measure the EGF contents in vitreous and serum in patients with proliferative diabetic retinopathy (PDR) 16 cases, proliferative vitreoretinopathy (PVR) 20 cases, central retinal vein occlusion (CRVO)16 cases,other retinal vascular diseases 5 cases,and controls 10 cases. RESULTS:The EGF levels in vitreous of the patient group were apparently higher than those of the controls (Plt;0. 001). Among patient group,the EGF contents in vitrectomy fluid was lower than that of original vitreous, reflecting about 60~ 63~ EGF level in original vitreous, Both showed positive correlation. To compare the EGF contents in serum of patients and controls,the EGF contents in serum of PDR group increased significantly. In CRVO group the EGF contents also increased,while in PVR group,the EGF contents were lower than those of the controls. CONCLUSIONS: The increased EGF contents in vitreous of patient group may play a role in the pathogenesis of proliferative retinal diseases. The RRA is a sensitive method for quantitative measurement of growth factor. （Chin J Ocul Fundus Dis,1996,12: 91- 93）