Abstract: An external culture of three human cancer cells were used to study the effect of Ascorbic Acid(Vc) on the multiplication,the survival,and the content of living cell protein of cells.Human hepatic carcinoma cell line(Q3),human throat carcinoma cell line(HEP-2) and human gastric carcinoma cell line(SGC) were studed with technique of cell cultrue.The results showed that the different concentratrations of ascorbic acid inhibite carcinoma cell lines growth differently.The resuls also suggested that a proper use of ascorbic acid might be beneficial in the prevention of and might act as an adjuvant treatment of human cancer.