Abstract: Objective　To study the expression and the significance of Cystatin B and Cystatin C in tongue squamous cell carcinoma as well as the function. Methods The data and the samples of 50 patients with tongue squamous cell carcinoma treated in Department of Oral and Maxillofacial Surgery, School of Stomatology, China Medical University from January 2010 to January 2011 were collected. Cystatin B and Cystatin C expression levels in tumor or adjacent normal tongue were examined with immunohistochemical method. Statistical analysis was performed. Results　Positive expression rates of Cystatin B in tongue squamous cell carcinoma cancer and adjacent normal tongue mucosa were 72.0% (36/50) and 36.0% (18/50), and the difference was statistically significant(P<0.05).The positive expression rate of cyatatin C were 68.0%(34/50) and 38.0%(19/50), and there was significant difference (P<0.05). Cyatatin B and Cystatin C were all correlated with pathological grades, and not correlated with patient's age, gender and the presence of lymph node metastasis. Conclusion　Cystatin B and Cystatin C may play some role in diagnosis of tongue squamous cell carcinoma and pathological grading.

Key words: tongue squamous cell carcinoma, Cystatin B, Cystatin C