Objective In order to study the effect on chondrocyte proliferation and the mechanism of treating osteoarthritis(OA) by XBL,the experimant is carried out.Method The first－ subcuiture chondrocytes are implanted into two 96－ foramen culture plates and sixteen culture flasks.After 24 hours in cubation 8 groups are divided into as follows:No 1 group(control)5％ serum DMEM No,2～ 7 groups(XBL)5％ serum,0.5％ 、 1％ 、 2％ 、 4％ 、 8％ 、 16％ XBL－ DMEM are added respectively.NO 8 group no cell incubation.After culture of 24 and 48 hours ,two plates are detected for viablilty and proliferation respectively by MTT method(Light absorption value A),cell total protein is assessed by comassie Brilliatnt G－ 250 colormetric assay.Result 2％ ～ 8％ XBL can promote the proliferation and protein synthesis of chondrocyte.Conclusion XBL can protec degradation from Matrix metallo protzinase and decrease the impairment of chondrocyte.