Abstract: Objective : To investigate the value of γ-glutamyl transpeptidase (γGT) in prevention of esophageal cancer, and search for the effective method reducing incidence and mortality of esophageal cancer in high incidence area. Methods : The 451 cases of subjects with severe dysplasia were followed up 3 years with endoscopic examination, the pathology, cytology and reaction of γ-GT. Results : After 1 year follow-up, there were 17 cases with cancer in 231 cases with γ-GT positive and without cancer in 95 cases with γ-GT negative. In 215 cases with 3 years follow-up, the subject with negative γ-GT reaction or positive γ-GT reaction below 40 years old didn’t detect esophageal cancer.The cancerous incidence of the subject with both severe dysplasia I and II and positive γ-GT reaction was 5.7M and 14.3M respectively. Conclusions : These findings suggested that γ-GT should be a cancerous risky classification marker of esophageal epithelial dysplasia. The subjects with severe dysplasia should be classified according to γ-GT reaction in prevention of esophageal cancer. As long as positive γ-GT reaction combination with severe dysplasia is adopted in the prevention of esophageal cancer, the population of prevention of esophageal cancer was more definitely, and the ratio between the expense and benefit for strategy of prevent and treatment in esophageal cancer should be increased.