The development, invasion and metastasis of tumors are complex processes in which multi-factors and multi-stages are involved. Cadherins play important roles in these processes. The structure and function of the epithelium- cadherin（E-cad）protein and the promoter methylation of E-cad gene are briefly introduced in this article. The relationship of promoter methylation of E-cad gene and the development, invasion and metastasis of head and neck carcinoma are also reviewed.
