Abstract: OBJECTIVE To investigate the inhibition effects and underlying mechanism of Ginsenoside Rg1 on IL-1β induced cartilage degradation. METHODS The synovial membrane and cartilage tissue of Osteoarthritis patients were collected and cultured into fibroblast synoviocytes. The FLS cells were stimulated by IL-1β， and co-cultured with chondrocytes. We divided the experiment into different groups， including the blank group， the IL-1β group and the different concentration Rg1 groups. We observed the degradation of cartilage tissue was observed by staining with red O， and real-time fluorescence quantitative PCR was used to analyze the gene expression of MMPs， and the expression of MMP-3 in the supernatant was detected by ELISA， also the Western blot analysis was employed to determine the related proteins in NF-κB pathway. RESULTS Rg1 significantly inhibited the degradation of cartilage induced by IL-1β to protect the cartilage. The protective effect of Rg1 on cartilage was mainly contributed to its inhibition on MMPs， especially by inhibiting the MMP-3 gene and protein expression in the synovial fibroblasts. Rg1 inhibited the expression of MMP-3 mainly through NF-κB pathway. CONCLUSION Rg1 can inhibit the cartilage degradation induced by IL-1β and play the role of cartilage protection， mainly by inhibiting the expression of MMP-3 gene and protein in FLS.