ObjectiveTo investigate the regulation of human bone marrow mesenchymal stem cells (hBMSCs) osteogenic and adipogenic differentiations mediated by Wnt10b adenoviral vector in vitro. MethodsThe hBMSCs from ilial bone tissue in adults at passage 4 were infected by Wnt10b gene expression adenoviral vector (group A), Wnt10b-shRNA adenoviral vector (group B), and empty vector (group C), and non-transfected hBMSCs served as the blank control group. Then the cells were cultured separately in the circumstance of osteogenic induction, adipogenic induction, and non-induction. The alkaline phosphatase (ALP) staining, alizarin red staining, and oil red O staining were used to detect the osteogenic and adipogenic differentiations; real-time fluorescent quantitative PCR and Western blot were used to analyze the expressions of osteoblast and adipocyte genes and proteins. ResultsThe results of ALP staining were positive after osteogenic induction, group A showed strong staining, and group B showed the weakest staining. The results of alizarin red staining showed that there were a lot of patchy confluent brown mineralized nodules in group A; a few punctate brown mineralized nodules were seen in group B; and many punctuate brown mineralized nodules were found in groups C and D. The results of oil red O staining showed strong staining in groups B, C, and D after adipogenic induction, especially in group B; scattered or small clustered staining was observed in group A. The expressions of osteoblast genes and proteins were significantly higher in group A than groups B, C, and D, and in groups C and D than group B by real-time fluorescent quantitative PCR and Western blot test; however, the expressions of adipocyte genes and proteins showed a contrary tendency. ConclusionThe high level expression of Wnt10b can enhance osteogenic differentiation of hBMSCs, and the low level expression of Wnt10b can increase adipogenic differentiation of hBMSCs.