【Abstract】Objective To investigate the effect of cotransplantation of bone marrow mesenchymal mtem cells (BMSCs) and olfactory mucous neural stem cells (OMNSCs) on motor function after spinal cord injury in rats. Methods Rat BMSCs and OMNSCs were extracted and cultured. 60 male specific pathogen free (SPF) grade sprague dawley (SD) rats were randomly divided into (1) control group which only underwent laminectomy without damaging the spinal cord; (2) sham group which 5μL of normal saline was injected into the injured area; (3) BMSCs transplantation group which 5μL BMSCs single cell suspension (5×104 cells) was injected into the injured area; (4) OMNSCs transplantation group which 5μL OMNSCs single cell suspension (5×104 cells) was injected into the injured area; (5) BMSCs and OMNSCs cotransplantation group which 5μL BMSCs and OMNSCs (1:1) cell mixture (5×104 cells) was injected into the injured area. Bassobeattlebresnahan (BBB) scores were evaluated on 1, 3, 7, 14 and 28 days after cell transplantation, respectively. After 28 days, the rats were killed and spinal cord tissue was isolated and the immunofluorescence staining was used to observe the cell migration. Results After modeling, the rats' hind limbs were paralyzed, and the BBB score was 0 points. At 14 days after transplantation, the motor function of the stem cell transplantation group was significantly improved compared with the simple spinal cord injured, and the BBB score was statistically significant (P＜005). Compared with the BMSCs transplantation group and the OMNSCs transplantation group, the BBB score of the cotransplant group was significantly increased at 21, 28 days after transplantation (P＜005). The results of immunofluorescence observation showed that 28 days after spinal cord injury, vacuoles were found in the spinal cord of the injured area, and two kinds of stem cells gathered around the vacuoles. The distribution of BMSCs in the damaged area was more concentrated, while the OMNSCs was relatively scattered, and the OMNSCs were more extended. Conclusion Stem cell transplantation can restore motor function of spinal cord injury rats to a certain extent. The cotransplantation effects of BMSCs and OMNSCs stem cells are better than single cell transplantation.