Abstract: To observe the proliferative effects of Epimedium brevicornum Maxim and plateletrich plasma (PRP)， respectively， on SD rat chondrocyte， and to explore their synergic effect between each other, in vitro chondrocyte culter system was established using 3weekold SD rat knee cartilage. MTT and flow cytometry assays were adopted to test the chondrocyte prolifereation. Results: （1） PRP has significant proliferative effect on chondrocyte (P<001); （2） Epimedium brevicornum Maxim has a bit proliferative effect on chondrocyte; （3） Epimedium brevicornum Maxim combined with PRP has inhibitory effect on chondrocyte (P<001). Epimedium brevicornum Maxim combined PRP has inhibitory effect on chondrocyte (P<001)， deducing that some components in Epimedium brevicornum Maxim inhibited PRP growth factors and then decrease PRP activity. The conclusion needs further investigation．

Key words: osteoarthritis, Epimedium brevicornum Maxim, plateletrich plasma, chondrocytes, proliferation