Abstract： Objective To evaluated the clinical characteristic and 30-day clinical outcomes of acute inferior wall ST-elevation myocardial infarction from occlusion of the left circumflex artery (LCX) and the right coronary artery (RCA).Methods From January 2008 to December 2011,621 acute inferior wall ST-elevation myocardial infarction patients who underwent primary pereutaneous coronary intervention(PCI) were enrolled in a single center retrospective study.Of621 cases,515 patients were enrolled in RCA group and 106 patients in LCX group.Results There were no significant differences between two groups in terms of age,sex,hypertension,diabetes,smoking,diastolic pressure,ischemia time ( all P ＞ 0.05 ).The proportion of combined with right ventricular acute myocardial infarction,the sum of ST-elevation and left ventricular ejection fraction were remarkably higher in group RCA than those in LCX group[29.3％ (151/515) vs 4.7％ (5/106),(11.0 ±2.8)mm vs (9.8 ±3.3) mm,(57 ± 12)％ vs (55 ± 10)％ ],while systolic blood pressure,the peak level of creatine kinase-isoenzyme,troponin Ⅰ and 30-day mortality in group RCA were lower[ ( 119 ± 29)mm Hg vs (126 ± 31 )mm Hg,(47 ± 30)μg/L vs (55 ± 33 ) μg/L,( 160 ± 71 ) U/L vs ( 176 ±73)U/L,3.9％ (20/515) vs 8.5％ (9/106) ] (all P ＜0.05).There were not significant difference in thrombolysis in myocardial infarction(TIMI) 0 flow,multiple-vessel disease,procedural time,door to balloon time,final TIMI 3 flow and intra-aortic balloon pump support between the group RCA and LCX group [64.5％ (332/515) vs 57.5％ (61/106),51.7％ (266/515) vs 49.1％ (52/106),(50 ± 22) min vs (55 ±27)min,(77 ± 13)min vs (79 ± 12)min,93.4％ (481/515) vs 92.5％ (98/106),8.2％ (42/515) vs 7.5％ (8/106),all P ＞0.05].Multivariate analysis demonstrated that LCX was a risk factor of 30-day mortality( OR =1.167,95％ CI:0.992-1.963,P =0.033 ).Conclusions The electrocardiograph of occlusion of the left circumflex artery is atypia.The 30-day prognostic outcome is poorer in LCX-related acute inferior wall myocardial infarction.