To evaluate the expression of HAase in Oral Squamous Cell Caricinoma (OSCC).

The distribution and expression of HAase in 21 patients with OSCC and their resecetions with tumor-free margins were examined by immunohistochemistry method.

HAase were mainly immunostained in tumor tissue. The expression of HAase in oral cancer with nodal metastasis and low pathological grades were higher than that with no nodal metastasis and high pathological grades (P < 0.05), whereas no difference between the TNM stages (P > 0. 05).

The HAase levels were high in oral squamous cell carcinoma tissues, and rising in patients with lymph node metastasis and poorly differentiated.