The studies of immunohistochemistry, histochemisu3r and electron microscopy in 50 patients with retinoblastoma were carried out. Our results show that retinoblastoma origin from primitive retinal neuronal cells that can differentiate into nmture neuron (including retinal photoreeeptor) and glial cells.The glial component in the retinoblastoma is mainly reactive glial proliferation.There is a good prognosis in the patients with retinoblastoma in which there are a lot of differiation areas and glial proliferation. （Chin J Ocul Fundus Dis,1993,9:193-197）