ObjectiveTo detect FoxM1 expression in thyroid papillary carcinoma TPC-1 cells,and explore influence of FoxM1 expression on important genes (RAS gene and CDK1 gene) of mitogen activated protein kinase (MAPK) signal pathway. MethodsThe hFoxM1-RNA interference was used to deal with the thyroid papillary carcinoma TPC-1 cells (experiment group),another untreated TPC-1 cell was as control group.Then the real-time quantitative PCR was used to detect the FoxM1,Ras,and CDK1 gene expressions in all the TPC-1 cells. ResultCompared with the control group,the FoxM1 gene expression was significantly decreased (0.452 9 versus 1.005 0,t=24.692 9,P<0.01),the Ras gene expression was significantly elevated (1.319 0 versus 1.001 2,t=14.218 5,P<0.01),and the CDK1 gene expression was significantly decreased (0.767 5 versus 1.008 1，t=10.763 4,P<0.01) in the experiment group. ConclusionFoxM1 gene expression level in thyroid papillary carcinoma TPC-1 cells could influence Ras and CDK1 expression,which suggests that its role in thyroid papillary carcinoma might be associated with MAPK signal pathway.