Objective To observe the application of intra-aortic balloon counterpulsation(IABP)in patients with acute myocardial infarction(AMI).Methods 1206 eases of AMI were selected consecutively.505 cases received successful reperfusion therapy and 701 cases received medical conservative therapy.464 cases were with anterior infarction,474 cases with inferior/posterior infarction and 268 cases with non-ST elevated MI(NSTEMI).There were 89 cases with cardiogenic shock(CS).Intra-aortic balloon pump(IABP)was used in patients accompanied with CS.cardiac rupture or papillary muscle dysfunction,left main or three vessel lesions with hemodynamic stability,pulmonary edema or ventficular arrhythmia in the course of PCI.Patients with IABP were divided into two groups according to juncture of IABP,early group(IABP was used in hemodynamic stability or within 1 hour of CS)and late group(IABP was used in hemodynamic instability or after 1 hour of CS).Results ①IABP was used in 97 patients.CS accounted for 45.3%(44/97),high risk PCI took 21.7%(21/97),hemodynamic instability was 15.5%(15/97).Mean duration of IABP insertion was 3.8 days.②In patients with IABP,successful reperfusion of death group[45.7%(16/35)vs 66.1%(41/62),P=0.041]and early IABP insertion group[25.7%(9/35)vs 91.9%(57/62),P=0.000]were fewer than that of survival.Accompanied with Cs[82.9%(29/35)vs 24.2%(15/62),P=0.000],cardiac rupture[20%(7/35)vs 0(0/62),P=0.000],urea nitrogen[(8.8±2.4)mmol/Lvs(6.3±1.0)mmol/L,P=0.040]and creatinine[(132.6±35.4)umol/L vs(79.6±17.7)μmol/L,P=0.000)]of death group were higher than that of survival.③Logistic regression analysis showed that CS(OR=0.066,CI 0.018-0.241,P=0.000)and juncture of using IABP(OR=0.219,CI 0.062-0.778,P=0.019)were the independent risk factors for death.Conclusion Using IABP earlier in high risk patients with AMI may reduce in-hospital mortality.