All trans retinoic acid(ATRA)has widely biological effects,which can regulate the proliferation and differentiation of cells.The purpose of the experiment is to investigate the function of ATRA on the proliferation and adipogenesis differentiation of porcine adipose mesenchymal stem cells(AMSCs).The effects of ATRA on proliferation and adipogenesis differentiation of AMSCs were detected by MTT and quantitation of Oil Red O staining respectively;the morphologic changes of adipogenesis differentiation were analyzed by Oil Red O staining.The differentiation of AMSCs to adipocyte was also verified by expression of special adipogenic marker genes LPL and aP2 through RT-PCR.These results show that physiological concentrations(1×10-9~1×10-8 mol/L)and pharmacological concentrations(1×10-7~1×10-5 mol/L)ATRA have no effect on the proliferation of porcine AMSCs.These results of quantitation of Oil Red O staining show that physiological and pharmacological concentrations ATRA blocks the Adipo-genesis differentiation of porcine AMSCs significantly besides 1×10-7 mol/L(P 0.05).The result of RT-PCR show that ATRA significantly inhibits the expression of adipogenic marker genes LPL and aP2(P0.05).