Abstract: Objective:To analyze the influence factors of symptom-to-balloon time during percutaneous coronary intervention(PCI) in myocardial infarction patients with ST-segment elevation.Methods:Data of 47 patients with ST-segment elevation myocardial infarction who received primary PCI during October 2012 to February 2014 were analyzed.All these patients were divided into group A(attributed the symptoms to angina pectoris) and group B(not attributed the symptoms to angina pectoris);group C(clinical pathway group) and D group(not clinical pathway group).The symptoms to visit time,whether to use the emergency service system,communication time,communication to signature time,clinic to balloon time,PCI operation time,transfer to catheter room time were compared between group A and B;the time for communication,communication to signature time,clinic to balloon time,PCI operation time,transfer to catheter room time were compared between group C and D.Results:Compared with group B,the symptoms to treatment time,door to balloon time in group A were shortened(P<0.01 and P<0.05),the proportion of admission through emergency service system were higher(P<0.01),no differences between the communication to signature time and PCI time(P>0.05).Compared with group D,in group C,the admission to communication time,communication to signature time,transport time,door to balloon time were shortened(P<0.01),and no difference in PCI time,admission to communication time(P>0.05).Conclusions:Attributed the symptoms to angina pectoris can significantly shorten pre-hospital delay and balloon time.The implementation of clinical pathway can shorten door to balloon time.If the ratio of communication time in door to balloon time was long,it will affect door to balloon time.