Objectives: To investigate the isolation of mononuclear cells from bone marrow and evaluate the efficiency of mesenchymal stem cell proliferation in the culture process. Research methods: Bone marrow fluid from patients with acute traumatic brain injury, Cross-sectional descriptive. Results: The total number of mononuclear cells after isolation is 373.74 x 106 cells and the survival rate is over 90%. The average number of days of culture is 12.44 days, the efficiency of cell development reaches 86.29%. The percentage of MSC positive for mesenchymal stem cells markers averaged 93.11% and the average survival rate was 96.48%. Conclusion: Mononuclear cells can be collected after isolation from human bone marrow with high survival rates. During culture, the cell development efficiency is quite high, the cells obtained after culture contain mesenchymal stem cell populations.