Abstract： Objective To estimate the effects ot rosiglitazone on cultured HaCaT human keratinocytes and their possible mechanism.Methods HaCaT cells were cultured and treated with different concentrations ( 10,20,40,80 μ mol/L) of rosiglitazone or solvent for 24,48,72 and 96 hours,respectively.Cell proliferation was detected with methyl thiazolyl tetrazolium (MTT) assay.Western blot was performed to measure the protein expression of β-catenin and cyclin D1.Results Compared with the solvent-treated cells,the proliferation of HaCaT cells was significantly inhibited by 18.9％,23.7％,35.1％ and 44.6％ (all P＜ 0.05) after treatment with rosiglitazone of 10,20,40 and 80 μmol/L,respectively,for 48 hours.The expressions of β-catenin and cyclin D 1 were significantly lower in rosiglitazone-treated HaCaT cells than in solvent-treated cells (all P ＜ 0.05).Conclusion Rosiglitazone could inhibit the proliferation of HaCaT cells,likely by downregulating the expressions of β-catenin and cyclin D 1.