The invention discloses that the SKA3 gene can be used as a molecular marker for the diagnosis of endometrial cancer. Experiments prove that the expression quantity of the SKA3 gene in the endometrial cancer tissue is high in comparison with normal endometrial tissue. The invention also discloses that the SKA3 gene also can be used for preparing a medicine for treating endometrial cancer. The research result of the invention provides a new method for clinical diagnosis of endometrial cancer as well as a new target for the medicine for treating endometrial cancer.