PURPOSE:To observe tbe development of structure of the retinal blood vessels in human fetuses. METHODS:The retinas of 134 human fetuses from 12-weeks of fertilization to full term and of 4 adults were collected,and examined with immunohlstoebemical method. RESULTS:The examinations showed:(1)The spindle ceils only existed in the retinas of fetuseslt;27 weeks. Till full term,the vessels in ganglion cell layer(GCL)was still budding. (2)BM of all arterioles,venules and capillaries within the retinas of all fetuses and adults,was immunostained after exposure to antlsera against fibronectin.The laminin(LN)and type Ⅳ collagen(COL-Ⅳ)immunoreactive product appeared outside tbe endothelial cells of blood vessels in GCL at 25 weeks and 29 weeks,and tile b LN and COL-Ⅳ immunostaining around four layers of the retinal vessels in tile shape of sbeath appeared at 29 weeks and 32 weeks respectively. (3)As soon as the cords of the endothelial cells were canaized,the smooth muscle cells and perieytes appeared outside the walls. (4)While four layers of the retinal vasculature was spreading to the ora serrata,the glial limitans was formed outside the endothelial cells by the processes of astrocytes and Muuml;ller cells. CONCLUSIONS:Comparing with the adults,certain de fleieneies of the structure of the retinal vessels exisl in the human fetus,and tile endnthelial cells in the retina of the full lerm fetus arc still in proliferation and migration. (Chin J Ocul Fundus Dis,1997,13:153-156)