〔Abstract〕 Objective To investigate the relationship between miR-26 b and Wnt/β-catenin signal pathway, different differentiation states of mesenchymal stem cells(MSCs) and its role in the chemotaxis of MSCs to hepatocyte growth factor(HGF).Methods MSCs derived from rat bone marrow were cultured in serum-free induced differentiation medium for 0 d, 7 d, 14 d and 21 d, respectively. The models of MSCs differentiation at different stages of liver-like differentiation were established.The expression of miR-26 b in different differentiated MSCs cells was detected by qRT-PCR. The recombinant adenovirus(Ad-26 b) was used to infect MSCs to achieve high expression of miR-26 b, and the empty virus infected MSCs was used as the control(Ad), the expression of active-β-catenin(ABC), p-β-catenin, β-catenin and the transcription level of Wnt/β-catenin classical target genes c-Myc and RUNX2 were detected. The effects of Transwell and Dunn chamber on the spreading area and adhesion spot of MSCs were determined, and their effects on the chemotaxis and migration of MSCs in different differentiation states were compared.Results With the prolongation of differentiation time, the miR-26 b expression of MSCs increased, and the expression of miR-26 b reached the peak at 14 d after differentiation, and the difference was significant compared with the control group(P<0.05). After high expression of miR-26 b, the level of ABC protein increased,the protein level of p-β-catenin decreased,but the total protein of β-catenin did not change significantly. The expression of downstream target gene c-Myc and RUNX2 of Wnt/β-catenin signal was significantly up-regulated. High expression of mi R-26 b could made the spreading area of MSCs smaller and show polar distribution,and the number of fine adhesive plaques of MSCs increased significantly and distributed to the periphery of the cell front end. Transwell and Dunn chamber experiments showed that the chemotactic migration ability of MSCs to HGF in the induced differentiation group was significantly higher than that in other groups,and the chemotactic migration ability to HGF in the high expression mi R-26 b group was significantly higher than that in the control group( P<0. 05). Conclusion Mi R-26 b affects the differentiation and chemotaxis of MSCs by regulating the Wnt/β-catenin signal pathway.