Objective To explore the effect of cartilage defect repair using engineered chondrocyte composite through autologous bone marrow mesenchymal stem cell (ABMSC) cultured on the sodium alginate scaffold in rheumatoid arthritis (RA).Methods Eight patients with RA were divided into control group (4 patients) and alginate scaffold treatment group (4 patients) at random.Engineered chondrocyte composite with alginate scaffold were injected in treatment group and saline injected in control group.Knee biopsy tissue was extracted in treatment group and control group after one month of the treatment.Pathological changes of articular tissue were observed by HE and immunohistochemical techniques in treatment group and control group.Immunohistochemical positive stained type II collagen cells were counted and pathological changes of articular tissue were observed by light microscopy.Repair of articular cartilage defect was detected in control group and treatment group.Results Compared with control group，type II collagen positive cells remarkably increased and the number of inflammation cells in articular tissue reduced in alginate scaffold treatment group.The histomorphometric results showed that inflammation significantly reduced and the cartilage cells remarkably increased in treatment group.Conclusions Engineered chondrocyte composite with alginate scaffold can repair cartilage defect in RA.