Objective:To study the effect of curcumin on osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) in high glucose environment and its possible mechanism. MethodsRat bone marrow mesenchymal stem cells were isolated and cultured in vitro. The cells were divided into normal glucose concentration group,high glucose concentration group and high glucose + curcumin group. CCK-8 was used to detect the cell proliferation activity; The nuclear translocation of NF-kappa B p65 was detected by immunofluorescence staining and the expression of NF-kappa B p65 was detected by Western blot. The osteogenic ability was divided into three groups:normal glucose concentration osteogenic induction group, high glucose concentration osteogenic induction group and high glucose + curcumin osteogenic induction group, in which 2 mmol/L glutamine, 10 mmol/L β-glycerophosphate, 10 nmol/L dexamethasone and 50 mg/L ascorbic acid were added into every 100 ml α-MEM medium. Alizarin red staining was used to detect the formation of calcium nodules. The expression of Runx2 and OCN mRNA was detected by fluorescence quantitative PCR.  Results:After 7 days of inoculation and culture, BMSCs were found to grow clonally under inverted microscope, and after subculture, the cells extended into long fusiform. CCK-8 results showed that there was no significant difference in cell proliferation activity between the high glucose group and the normal group on day 1 and day 3 (P>0.05); The cell proliferation activity in the high glucose group was significantly lower than that in the normal group on day 5 (P<0.05); There was no significant difference in cell proliferation activity between the curcumin group and the high glucose group on day 1, day 3 and day 5 (P>0.05). Compared with the normal glucose concentration group, the activation of NF - κB p65 increased in the high glucose concentration group, while the curcumin group inhibited the nuclear translocation of NF - κB p65 in the high glucose concentration. Western blot showed that curcumin could inhibit the nucleoprotein expression of NF - κ B p65. After 14 days of osteogenesis induction, alizarin red staining showed a large number of mineralized nodules in the normal glucose concentration group, and only a small number of mineralized nodules in the high glucose concentration group. Curcumin treatment could significantly promote the formation of calcium nodules in the high glucose concentration group. The results of PCR showed that the expression of Runx2 and OCN mRNA in high glucose concentration group was significantly lower than that in normal glucose concentration group (P<0.05); The expression of Runx2 and OCN mRNA in osteogenic differentiation of BMSCs was significantly promoted in the high glucose + curcumin group (P<0.05).  Conclusion:Curcumin could promote osteogenic differentiation of bone marrow mesenchymal stem cells in high glucose environment. The mechanism may be related to the inhibition of activation of NF-κB p65 in high glucose concentration.