Abstract: Levels of serum total sialic acid (TAS) among 1510 subjects from cixian,one of the place highest incidence of esophageal cancer were detected by technique of chemical colorimetric method.The results show that TSA levels increase with extent of hyperplasia in esophageal epithelial cell.Analysis of variance show the difference of serum TSA levels were significant among esophageal cancer,near cancer,dysplasia Ⅱ and dysplasia I,hyperplasia,normal ( P 0 01).q test between all grading lesion show TSA levels were significant in dysplasia Ⅱ with normal ( P 0 01).While TSA levels were not in dysplasia Ⅰ with normal ( P 0 05).The assay indicate that levels of serum TSA may be helpful as a norm of early diagnosis of esophageal cancer among subjects.