Objective To investigate the rate of employing angiotensin converting enzyme inhibitors/angiotensin receptor blockers (ACEI/ARB) therapy in patients with acute myocardial infarction (AMI) in Gansu,Ningxia,Qinghai and Xinjiang provinces from 2001 to 2011,in order to determine the factors affecting the use of ACEI/ARB.Methods The original data of this study were obtained from the China PEACE,a national retrospective study of AMI to evaluate clinical outcome of coronary heart disease from 31 provinces.A part of these data was selected from 8 cooperative hospitals (2 hospitals were tertiary class and 6 hospitals were secondary class) from Gansu,Ningxia,Qinghai and,Xinjiang provinces for further analyses.The clinical data of AMI patients in 2001,2006 and 2011 were collected to analyze the use of ACEI/ARB therapy in each of these years.Binary logistic regression analysis was used to identify factors influencing the use of ACEI/ARB.Results Of 311 eligible patients included,300 were categorized into Class Ⅰ AMI and 11 into Class Ⅱ a AMI according to Chinese guidelines.From 2001 to 2011,there wassignificant change in the use of ACEI/ARB in term of percentage in patients with Class Ⅰ AMI (69.57％,82.19％ and 60.77％,P =0.033),but such change did not occur in patients with Class Ⅱa AMI (40％,0％ and 60％,P =0.525).Among three specific years,the percentage of ACEIs employed was noticeably higher than that of ARBs.Binary logistic regression analysis showed that patients with hypertension (OR =2.3,95％ CI:1.3-4.1),heart failure (OR =1.95,95％ CI:1.7-5.8),smoking indulgence (OR =2.0,95％ CI:1.2-3.6) were more likely to be treated with ACEI/ARB,and patients with prior stroke (OR=0.3,95％CI:0.1-0.8),systolic blood pressure ＜90 mmHg (OR =0.1,95％CI:0-0.5)were less likely to be treated with ACEI/ARB.Conclusiorns In underdeveloped areas such as Gansu,Ningxia,Qinghai and Xinjiang provinces,the overall proportion of rational and necessary use of ACEI/ARB use in patients with AMI during hospitalization is still low.The rational use of ACEI/ARB lags behind the advance of medical condition progress,economic development and information availability,especially in patients with a history of stroke,low blood pressure.Patients with hypertension,heart failure,smoking indulgence were more likely to get ACEI/ARB therapy.The main reasons of this phenomenon were attributed to firstly the thorough understanding of standard medication guide to coronary heart disease to be lacking among some professionals,secondly,the side effects of these drugs to be unnecessary worried about among certain of doctors,and thirdly,low awareness of the pathogenesis of AMI disease and the lack of concerning for patients to be existent.