〔Abstract〕 Objective To investigate the effects of interleukin(IL)-10 on the proliferation of HaCaT cells and CaCl2induced expression of differentiation markers and its possible molecular mechanisms. Methods HaCaT cells were treated with various concentrations of IL-10(0, 3, 10, 30 ng/ml) for different time(0, 24, 48, 72 h), cell proliferation was measured using MTS, and cell cycle was determined by flow cytometry. HaCaT cells were pretreated with IL-10(final concentration 10 ng/ml) for 1 h, then incubated with or without CaCl2(final concentration 1.2 mmol/L) for 24, 48, 72 h, Western blot was performed to detect the effect of IL-10 on the expression of HaCaT keratinocyte differentiation markers. After pretreatment of HaCaT cells with PD98059, an inhibitor of mitogen-activated kinase-ERK1/2, and LY294002, an inhibitor of phosphatidylinositol kinase-serine/threonine kinase(PI3K-AKT), the total RNA and proteins were extracted separately, real time quantitative polymerase chain reaction(RT-qPCR) and Western blot were used to examine the influence of IL-10 on the expression of differentiation markers(Keratin1, Keratin5, Involucrin). Results MTS results revealed that IL-10(30 ng/ml and lower doses) did not alter the proliferation of HaCaT cells in 72 h. Flow cytometry analysis demonstrated that IL-10 had no significant influence on cell cycle progression. The results of Western blot showed that IL-10 upregulated the expression of differentiation markers Involucrin, while there was no significant effect on Keratin1 and Keratin5. Mechanism research analysis demonstrated that IL-10 could activate ERK1/2 and AKT, increase their phosphorylation levels; RT-qPCR and Western blot results showed that PD98059 and LY294002 partially blocked IL-10 induced Involucrin expression. Conclusion At a particular concentration range, IL-10 has little effect on HaCaT proliferation, but it partially upregulates the expression of differentiation marker Involucrinviathe MAPKs-ERK1/2 and PI3K-AKT pathways.