Results showed that PER1 expression was significantly down-regulated in cancerous tissues of patients with BSCC (P<0.05). PER1 expression was significantly down-regulated in patients of T3∼T4 staging and those with lymph node metastasis compared to that of T1∼T2 staging and those without lymph node metastasis (P<0.05), respectively. The gene discussed is PER1; the disease is metastatic malignant neoplasm in the lymph nodes.