Abstract: Adding different concentrations Licl （0 （control group）， 10，20，40 mmol/L），a specificity protein inhibitor of glycogen synthase kinase 3β （GSK3β），to the purification of the dairy cow mammary epithelial cells （DCMECs），after 24 h，this study detected the effects of GSK3β on cell proliferation and cell cycle in DCMECs，and using the Real-time quantitative PCR to test the effects of different concentrations Licl on GSK3β and Cyclin D1 mRNA level and Western blotting to test the effects of GSK3β/phosphorylated GSK3β (p-GSK3β) and Cyclin D1 protein expression levels in DCMECs. The results showed that Licl could improve proliferation in DCMECs，Licl inhibiting GSK3β certainly promote DCMECs proliferation and the optimal concentration of Licl was 20 mmol/L. Compared with the control group，GSK3β protein expression was restrained after adding Licl，p-GSK3β protein expression level up-regulation，Cyclin D1 protein expression level increased at the same time.These dates demonstrated that GSK3β was a negative regulatory factor of DCMECs on proliferation ability，the deactivation GSK3β through Cyclin D1 pathway could promote the process of cell cycle.

Key words: glycogen synthase kinase 3β ；dairy cow mammary epithelial cells；Licl；Cyclin D1；cell proliferation