【Objective】To study the function and mechanism of INI1 in human epithelioid sarcoma cells.【Methods】 Western blotting was used to test the expressionlevel of INI1in epithelioid sarcoma cells. The expression of INI1 in clinical specimens of epithelioid sarcoma was detected by immunohistochemistry.Tet-on system was used to establish the expres⁃ sion of INI1 in epithelioid sarcoma cells. Following the induction of INI1 expression，the cell morphology，proliferation and the molecular markers of adipocytic differentiation were detected. Then western blot was employed to detect the transcription factors of adipocytic differentiation，and oil red O staining was also tested.【Results】The expression of INI1 was absent in both epithelioid sarcoma cells and clinical tissues（P<0.05）. The INI1 expression in the epithelioid sarcoma cells was successfully established by Tet-on system.After induction by doxycycline，the expression of INI1 was up-regulated. With continuous expression of INI1，the morphology of VA-ES-BJ cells was changed，with the appearance of abundant vacuoles in the cytoplasm. The cell proliferation was obviously inhibited（P<0.05）. Epithelial cell marker Cytokeratin was found significantly reduced（P<0.05）. In addition，the adipocyte markers ，leptin adiponectin and lipoprotein lipase were significantly up- regulated（P<0.05）. The adipogenic transcriptional factors PPAR- γand CEBP- αwere found up-regulated（P<0.05）and the oil red staining was significantly positive.【Conclusions】The expression of INI1 was absent in epithelioid sarcoma.Reconstruction of the expression of INI1 could induce adipocytic differentiation via upregulation of transcriptional factors PPAR-γand CEBP-αin epithelioid sarcoma cells.