Abstract：In this study, using AO, Hoechst 33342 and flow cytometry methods, the apoptotic change of pig preadipocyte was investigated after treatment with 9-cisRA (RXRα ligand), and transfection of pRXRα-EGFP and RXRα-siRNA. The results showed that it occurred morphologic change of apoptosis in pig preadipocyte. Cellular shrinkage and round, condensation of chromatin adjacent to nuclear membrane, nuclear fragmentation of apoptotic bodies which were rapidly engulfed by neighboring cells. Moreover, compared with control group, apoptotic rate was significantly decreased in the groups of 10 nmol/L 9-cisRA supplement and pRXRα-EGFP（P0.05）. In contrast, apoptotic rate of the groups with 10 µmol/L 9-cisRA or RXRα-siRNA was remarkably higher than the control group （P0.05）. It suggests that RXRα can inhibit the apoptosis of pig preadipocyte.
