OBJECTIVE:To investigate the transporting function of subretinal fluid in retinal pigment epithelium(RPE) of experimental retinal detachment (RD). METHODS: Twenty-seven pigmented rabbits with one eye as retinal detachment model and the other eye as control were divided into 4 groups ,ic. 7 rabbits in each group at random. The Na十-K+-ATPase activity in RPE-choroidal tissue at the detached region in both experimental and control eyes was determined at the lst,2nd,3rd and 4th week after retinal detachment,and also the ultrastructure of the RPE-choroidal tissues observed. RESULTS:The activity of Na十-K+-ATPase of experimental eyesE[(2.16士1.26)/mu;mol(mgmiddot;h)]was significantly lower than that of the controis[(4.84plusmn;1.59)mu;mol/(mgmiddot;h)]. The degree of decreasing activity was relieving along with increasing of the course of RD. The inward pinocytosis in RPE cells under electron-microscope was found from the 2nd week samples afterwards and becoming obvious along with increasing of the disease course. CONCLUSIONS:The outward transporting function of RPE was increased after RD,it became decreased along with increasing of the course df RD and the inward transporting function then developed.