Lead-poisoned mouse(Mus muscculus)model was established by intraperitoneal injection of lead acetate. The pathological changes of liver and kidney were examined. The expression alterations of Caspase-3, Bcl-2 and Bax, two apoptosis-related proteins, were also measured. We found that acute lead poisoning caused hepatic and renal injury by inducing cell apoptosis. After lead poisoning, Caspase-3 expression was increased while the ratio of Bcl-2 to Bax decreased in a time-dependent manner. Significant difference in the expression level between control group and experimental group was observed after 48 h of lead exposure. These results suggest that lead poisoning causes hepatic and renal cell apoptosis probably by regulating the expression of Caspase-3, Bcl-2 and Bax.