Effects of transforming growth factor-beta (TGF-β) were investigated in human colorectal cancer, and the influence of cantharidinate in inhibiting TGF-β1 expression was explored. Relationships among TGF-β1 and sex, age, tumor size, tumor location, tumor stage were also analyzed. H and E and immunohistochemistry staining were employed to assess colorectal cancer and TGF-β1 expression, respectively. Then, HCT-116 CRC cells were randomly divided into four groups, controls, no serum-treated, chemotherapy and cantharidinate-treated. Immunohistochemistry and real-time PCR were employed to assess the expression of TGF-β1 in CRC cells. Our data showed that the expression of TGF-β1 might be associated with tumor size and tumor location (P<0.05). The expression of TGF-β1 in CRC groups was higher than in adjacent groups (P<0.05). In addition, the expression of TGF-β1 in cantharidinate-treated group was much lower than in CRC group (P<0.05). Taken together, these results suggest that TGF-β1 plays an important role in CRC development. Cantharidinate might inhibit the expression of TGF-β1 and control the development of colorectal cancer.