Abstract: A randomized double blind intervention treating esophageal precancerous lesions with calcium was carried out in the populations of Huixian County Henen province，a high risk area for esopgaheal cancer. After one year, whether the calcium supplemetation group or the placebo group,the basal cell hyperplasia and esophagitis were improved,including endoscopy,histology and H-TdR radiography. It appeared not variance statisticaly between the calcium group and the placebo group (P>0.05). The blood calcium levels of subjects in the calcium and the placebo groups after intervention trial were not variance (P>0.05). Therefure, it is uncertain whether oral calcium supplementation protect from esophageal cancer.