Abstract： Objective To observe the changes of cell apoptosis and levels of Bcl-2 and Bax protein in myocardium after cardiopulmonary resuscitation (CPR) in rats and to study the protective effects of different doses of exogenous phosphocreatine (creatine phosphate, CP) on cell apoptosis. Methods A total of 32 male adult SD rats were randomly divided into 4 groups, namely control group ( group A), CPR group (group B), low dose CP group (group C, phosphocreatine 0. 5 g/kg given at beginning of CPR and 1.0 g/ kg 2 hour after CPR) and high dose CP group ( group D, phosphocreatine 1.0 g/kg at beginning of CPR and 2. 0 g/kg 2 hours after CPR) . Cardiac arrest was induced by asphyxiation and CPR was started 7 min after asphyxiation it groups B, C and D. Myocardium samples were taken 24 hours after CPR for detecting myocardium cell apoptosis by TUNEL method. The levels of Bcl-2 and Bax protein were measured by using immunohistochemistry. Experimental data were processed with variance analysis in SPSS package. Results Compared with group A, myocardium cell apoptosis index (AI), and the levels of Bcl-2 and Bax proteinincreased significantly in groups B, C and D (P ＜0. 01 ), and Bcl-2/Bax ratio decreased significantly (P ＜0. 01 ) . Compared with group B, myocardium cell AI and levels of Bcl-2 and Bax protein decreased significantly in groups C and D ( P ＜ 0. 01 ), and Bcl-2/Bax ratio increased significantly ( P ＜ 0. 01 ) .Compared with group C, myocardium cell AI and levels of Bcl-2 and Bax decreased significantly in group D (P ＜ 0. 05 ), and Bcl-2/Bax ratio increased significantly ( P ＜ 0. 05 ) . Conclusion Exogenous phosphocreatine, especially inlarge dose, could inhibit apoptosis of myocardium cells and alleviate myocardium injury after CPR in rats.