PURPOSE:To investigate the content of vascular endothelial growth factor (VEGF)in vitreous of patients with retinal vascula'r proliferative diseases. METHODS:The concentration of VEGF in undiluted vitreous samples from patients with retina vein occlusion (RVO) (n=7),Eales disease (n=7)and controls (n=7) was measured by enzyme linked immunosorbent assay (EL1SA). RESULTS:The levels of vitreous VEGF were significantly higher 13 folds in patients with RVO(4.67plusmn;3.38)ng/ml and 5 folds in patients with Eales disease(1.79plusmn;0.44)ng/ml than in controls (0.35plusmn;0.15)ng/ml separately(P＜0. 01). CONCLUSIONS:VEGF might play a part in mediating the neovascularization of retinal vascular diseases. （Chin J Ocul Fundus Dis,1997,13:171-173）