The stimulating effects of subretinal fluid (SRF) containing different molecular weight proteins which were isolated by fast performance liquid chromatography (FPLC) and ultrafiltration on the proliferative vitreoretinopathy (PVR) were investigated. The results showed that (1) the PVR was induced by 10-30 kD proteins injecting vitreously, and the forming duration of PVR was about two weeks; (2) the location of inducing PVR was mainly on medullary ray area in the rabbit eye; (3) In the SRF there were growth factors which were mainly those proteins with molecular weight between 10 kD and 30 kD.