Abstract: Objective: To establish a xenotransplanted subcutaneous tumor model of human endometrial carcinoma in nude mice. Methods: HEC-1B cells were cultured in vitro and collected. The cell suspension was injected subcutaneously into nude mice. When the subcutaneous carcinoma was approximately 0.8-1.0 cm in diameter, it was surgically removed and divided into pieces of 1-2 mm in diameter. The small pieces of tumor were then re-transplanted subcutaneously into newnude mice. The model was confirmed by histological analysis and electron microscopic observation. DNA content was analyzed by flowcytometry. Results: A subcutaneous xenotransplanted tumor model of endometrial carcinoma was established successfully in nude mice, and the tumor could be passed to new mice. Its characteristics were similar to human endometrial carcinoma. DNA index of HEC-1B cells in vitro and subcutaneous tumor cells that showed heteroploidy are 1.81±0.46 and 1.95±0.53, respectively. The malignant biological characteristics of the subcutaneous xenotransplanted tumor were similar to those of HEC-1B cells. Conclusion: The histopathology, immunohistochemical phenotype, ultrastructure, and DNA index character of the subcutaneous xenotransplanted cells were similar to those of the original tumor cells. Tumor transplant growth rate was 100%, suggesting that the biological characteristics of this model system are stable. The subcutaneous xenotransplanted HEC-1B tumor model in nude mice has the characteristics of human endometrial carcinoma and can be a useful tool for studying the biology, diagnosis and therapy of human endometrial carcinoma.