Abstract: Objective: To determine the expression of matrix metalloproteinase-12 (MMP-12) and its tissue inhibitor-1 (TIMP -1) in basal cell carcinoma (BCC) andcutaneous squamous cell carcinoma (SCC). Methods: The expression of MMP-12 and TIMP-1 proteins from the paraffin embedded sections of 25 patients with SCC, 31 patients with BCC and 20 normal controls were detected by immunohistochemical method. Results：The positivity rates of MMP-12 were 45.2% in the samples of BCC and 80% in SCC, which was higher than that in controls（P ＜0.05）. The positivity rates of TIMP -1 were 67.7% in the samples of BCC and 60% in SCC, which was lower than that in controls (P＜0.05). Conclusions: The high expression of MMP-12 and low expression of TIMP-1 may be associated with the development of SCC and BCC.

Key words: basal cell carcinoma, squamous cell carcinoma, matrix metalloproteinase-12, tissue inhibitor of metalloproteinase-1