In vitro cell models were used in this study to investigate the effect of different phenolics extracts of Chinese sumac （Rhus chinensis Mill.） fruits on cellular oxidative damage and 3T3-L1 differentiation at the cellular level. The results indicated that the three different solvent extracts and free phenolic fraction of Rhus chinensis Mill. fruits had good protection effects on the H2O2 induced oxidative damage of HepG2 cells and could significantly reduce the cellular ROS and apoptosis. In addition， those phenolic fractions could also significantly inhibit the differentiation of 3T3-L1 MBX preadipocytes. Results of the present work may supply scientific basis for further application of Rhus chinensis Mill. fruits.