Abstract: The purpose of the paper is to study the effects of levamisole (Lev)on nitrosamines-induced esophageal carcinogenesis.The test carried out in 82 Wistar rats,precancerous lesions of the esophagus were induced by MANA 5mg.kg^-1sc.Lev lOmg kg^-1and tilorone (Til)15mg kg^-1were administraed P.O.on the 5 days before MANA given.After 105 days of experiment,the incidence of precancerous lesions of the esophagus was determined and quantity of MANA in serum was tested by high performance liquid chromatography in rats.The results showed that lev had a significant decreases of the incidence of precancerous lesions of the esophagus and quantity of MANA in serum of rats similar to Til,but weight of rats was increased with normality by Lav and slowly by Til.It suggested that Lev and Til have similar preventive action to nitrosamines induced esophageal carcinogenesis,and Lev better than Til.