Abstract: BACKGROUND ＆ AIM： To explore the relationship of three proteins expression in esophageal mucosa epithelia between chronic esophagitis and esophageal para-cancer tissue. MATERIAL AND METHODS： Forty-seven cases of chronic esophagitis and 85 specimens with esophageal carcinoma and para-cancer tissue were analyzed by immunohistochemical staining for P53、P27 and MDM2 proteins expression. RESULTS： The P53 protein expression was not detected in normal mucosa， the positive rates of three groups, esophagitis, dysplasia epithelia and cancer tissue are similar(χ2=0.979, P=0.0615). From normal epithelium to chronic esophagitis and/or dysplasia to esophageal carcinoma, the positive-reactivity for P27 protein were detected. The differences for the four groups have no statistically significance(χ2=1.828, P=0.609).While the positive rates of MDM2 protein have statistically significance in the four groups(χ2=18.895, P=0.000).And are similar in normal epithelium, chronic esophagitis and dysplasia epithelia(χ2=3.585, P=0.167), and their positive rates are lower than esophageal carcinoma(χ2=14.802, P=0.301). The expressions of P53、 P27 and MDM2 proteins are similar in chronic esophagitis and mild, moderate and severe dysplasia epithelia(P53、P27, binomial distribution,minimum P=0.2140; MDM2,χ2=3.658,P=0.301). CONCLIUSION： The expression of P53、P27 and MDM2 proteins is similar in mucosa epithelia of chronic esophagitis and mild， moderate and severe dysplasia. This indicated that it is possible that chronic esophagitis is a kind of precancerous lesions.

Key words: esophagitis, esophageal para-cancer epithelia, oncogene proteins, immunohistochemistry