Objective:To isolate and culture the normal and degenerative nucleus pulposus cells (NPCs) and bone mesenchymal stem cells (BMSCs) of SD rats,and then to compare the effects of normal and degenerative NPCs on BMSCs differentiatinto nucleus pulposus-like cells by a 3D noncontact coculture methord. Methods:The animal models with degenerative nucleus pulposus were established by acupuncture and aspiration. The BMSCs,normal and degeneratived NPCs of SD rats were isolated and cultured. The cells growth condition was observed by light microscope,and the second generation of NPCs and dNPCs and the third generation of BMSCs were selecte to combine alginate gel stents and culture in transwell plate. The BMSCs+NPCs or BMSCs+dNPCs were co-cultured in vitro as experiment group;the NPCs and BMSCs were cultured alone as positive and negative control,respectirely. 7 days later,the collagenⅡ and aggrecan of recycled BMSCs of each group were detected by western blot and RT-PCR. Results:The mRNA of collagenⅡand aggrecan showed a high level both in two co-culture groups,but the BMSCs/NPCs co-culture group is more similar to NPCs sample than BMSCs/dNPCs co-culture group. The results of the content of collagenⅡand aggrecan was the same with mRNA level. Conclusion:Under a 3D non-contact co-culture system,both the normal and degenerative NPCs can induce BMSCs differentiation into nucleus pulposus-like cells,but the induction effects of normal NPCs is more obviously than degenerative NPCs .