Objective To observe the expressions of c-Ski in renal tissue of diabetic nephropathy rats, and discuss its significance. Methods Wistar male rats were randomly assigned to 3 groups: Control group, diabetic group and treatment group. Rats were killed at the 16th week after experiment. Histopathologic changes,in renal tissue were observed and immunohistochemistry was performed to investigate the expression of TGF-β1, α-SMA and c-Ski. Results The expression of c-Ski had a negative correlation with TGF-β1 and α-SMA. Compared to diabetic group, the expression of c-Ski was significantly increased in treatment group. Conclusion c-Ski may be a protective factor of tu-bular epithelial-myofibroblast transformation.