Objective To observe the morphological changes and gene expression during the transdifferentiation of adult retinal pigment epith elial(RPE) cells into neuronal phenotype in vitro induced by retrovirus and ciliary neurotrophic factor (CNTF). Meothds The adult RPE cells derived from CRL 2302 were infected by retrovirus with green fluoresence protein(GFP)and then were transfected further by liposome mediated CNTF expressing plasmid.The cellular ability of producing CNTG,and the expression of CNTF, CNTF receptor (CNTFR), and signal transduction molecule janus tyrosine kinases (JAK) were detected by enzyme linked immunosorbent assay, immunohistochemical stainin gand Western blotting method. Results After infected by retrovirus, the configuration of adult RPE cells didnrsquo;t change much, but expressions of neurons and some glial cells markers likeneurofilament (NF) protein and glial fibraillary acidic protein (GFAP) were detected. After further transfected by CNTF expressing plasmid, RPE cells which expressed CNTF highly and continuously had differential neurocytes; the expression of CNTFR didnrsquo;t change, but the distribution position changed to the cell membrane; expression of signal transduction molecule JAK increased obviously. Conclusion The adult RPE cells may transdifferentiate into neurons induced by retrvirus and CNTF. The transdifferentiation may relate to CNTF-CNTFR-JAK signal transduction pathway. (Chin J Ocul Fundus Dis, 2006, 22: 400-403)