PROBLEM TO BE SOLVED: To provide a method that can quickly and simply create a uterine sarcoma metastatic model animal having a primary tumor and a metastatic tumor of a uterus at the same time, and also to provide a model animal obtained by the method, the screening of medicine and the application of the model animal for effectiveness evaluation of treatment, an establishment method of the high metastatic strain derived from the uterine sarcoma, and an isolated cell useful for the creation method, etc.SOLUTION: A metastatic model animal creation method comprises: (a) a step of transplanting metastatic and tumorigenic cells in an immunodeficiency non-human mammal of a recipient derived from a uterine sarcoma； (b) a step of forming a tumor in the recipient animal and cutting the formed tumor to obtain a tumor piece； and (c) a step of transplanting the tumor piece in the myometrium of the immunodeficiency non-human mammal to serve as the model animal. The method is characterized in that the implanted tumor piece forms a metastatic tumor in a primary tumor nest and a target organ in the myometrium in the animal.SELECTED DRAWING: None
