Abstract: Snail was the first member of zinc finger protein superfamily，it plays a positive role in transcriptional control，formation of structure of suppressant chromation，cell signaling and growth. It can cause diseases because of control relaxation. Many researches have been discovered that Snail can induce epithelial-mesenchymal transition and E-cadherin and desmoglein degradation，Snail showed high expression in many tumor tissues ，such as in stomach，colon，liver cancer，ovarian cancer，head and neck squamous cell carcinoma，which was considered a contributing factor to tumor invasion and metastasis. Deep study of Snail can not only elucidate the mechanism of Snail，but also provide theoretical foundation for tumor treatment which take Snail as target spot. Reviews the structure，function of Snail and the relationship with tumor's growth and invasion.

Key words: Snail, structure and function, tumor