Hepatocytes in vitro damaged by carbon tetrachloride (CCL4) and high glucose(HG) were used to research the mechanism of CCL4 and HG on the glucokinase(GK) activity,the intercellular Ca2+ concentration and the level of tyrosine phosphorylation in cells ,and then the protective effects of Lycium bararum polysaccharides(LBP).The results showed that CCL4 and HG inhibited the GK activity,elevated Caconcentration and decreased the level of tyrosine phosphorylation in hepatocytes. LBP could improve the change of the GK activity and Ca2+ concentration induced by CCL4 and HG, and the decrease of tyrosikinase activity in the pathway of insulin induced by CCL4 only.But LBP couldn’t improve the decrease of tyrosikinase activity induced by HG.The conclusion was that LBP could protect hepatocytes against free radicals directly,but not against the damage of HG. This related to the different mechanism of CCL4 and HG.