Abstract: Objective :To study the gene expression profiles of human endometrial cancer at vari-ous differentiated grades and to identify the genes related to differentiation of endometrial cancer. Methods :cDNA microarray technology was used to analyze the differentially-expressed genes amongdifferent differentiated grades of 32 cases of endometrial cancer. Hierarchical cluster analysis (HCA) forthe gene expression profiles of the cases was employed. Results :The tissue samples were groupedbased on the various differentiated tumor grades with 33 differentiation-related genes identified (P<0.001). Based on the results from the HCA, the conformity rate was 91% among the 33 differentially-expressed genes and the analysis of pathological classification. Conclusion :Genes related to the differ-entiation of endometrial cancer can be identified, by using gene chips to analyze the expression profilesof endometrial cancer at various differentiated grades; HCA of the gene expression profiles can be help-ful in the recognition of high-risk endometrial cancers before surgery.