Abstract: Objective 　To investigate the expression of PPARγprotein and mRNA in large intestine cancer. Methods 　Human normal mucosa, colorectal adenoma and colorectal cancer specimens were taken f rom colonoscopic examination. Histopathological immunohistochemist ry staining was performed to examine the expression and localization of PPARγ protein and RT2PCR was used to detect the expression of PPARγ mRNA in human normal mucosa, colorectal adenoma and cancer. Results 　In human normal mu2 cosa, PPARγprotein was expressed in epithelial cells facing the colonic lumen, which were well differen2 tiated. However, it was expressed diffusely in adenoma. A st rong expression of PPARγprotein and mR2 NA was found in cancer cells, which was significant higher than colorectal adenoma and normal mucosa ( P < 0. 05) . The expression level of PPARγprotein and mRNA in normal mucosa and colorectal adenoma had no significant difference ( P > 0. 05) . The expression of PPARγ mRNA in high2grade dysplasia sub2 group had no difference with colorectal cancer ( P > 0. 05) and was higher than that of normal mucosa ( P < 0. 05) . Conclusion 　The location of PPARγ changed first in colorectal adenoma. PPARγ was ex2 pressed at relatively higher levels in high2grade dysplasia and colorectal cancer. These data indicate that PPARγmay involve early in the development of colorectal cancer.