Abstract: Objective :To explore the effect of Cadmium Chloride on killing of Hepatoma cellsand its mechanism. Methods :The MTT technique was used to observe the inhibitive effect s of Cad-mium Chloride against SMMC-7721、HepG2 and MCF-7 cell proliferation.MT concentrations were es-timated by the Cd-hemoglobin radioassay method. Apoptosis was confirmed by DNA ladder and analy-sis of DNA fragments. Results :Cd-induced cytotoxicity in SMMC-7721、HepG-2 and MCF-7 cellswas both dose-and time-dependent. apoptosis was the primary form of cell elimination after Cd expo-sure.The less metallothionein present the less a cell or tissue is resistant to cadmium induced cellapoptosis regardless of whether basal or induced MT was considered.The relationship between cellularMT content including basal and Zn-induced MT and Cd-induced apoptotic rates was negtive. Conclu-Sion :Cadmium Chloride can specially kill Hepatoma cells by promoting cell apoptosis.