Objective To observe the effect of CAEM-COLⅡnanofiber scaffolds composite with BMSCs in repairing articular cartilage defectof rabbits.Methods Cartilage acellular extracellularmatrix(CAEM)and collagenⅡ(COLⅡ)were mixed according to the ratio of 1∶1,nanofiber scaffolds were prepared by electrostatic spinning for cartilage tissue engineering.The second generations of bonemarrow stem cells(BMSCs)were inoculated onto the scaffolds.The cell scaffold composite was placed in the incubator for two hours.12 Japanese white rabbitswere randomly divided into the experimental group and the control group.In the experimental group,the cell scaffold composite was implanted into the articular cartilage defects of rabbits.In the control group,only the knee joint cartilage defects weremade.After 12 weeks,the animals were sacrificed and the repair effect was observed by gross appearance,HE staining and collagen typeⅡstaining.Resu lts General shape observation showed that cartilage defects in the experimental group were repaired well,and were filled with granulation tissue in the control group.HE staining showed that cartilage cavities formed in articular cartilage defects in the experimental group,and fibrous tissues were filled in the control group.In the repair area,collagen typeⅡstaining was positive in the experimental group,and negative in the control group.Conclusion The CAEM-COLⅡnanofiber scaffolds composite with BMSCs could well repair the articular cartilage defects of rabbits,and have potential of application in tissue engineering cartilage.