Objective：To explore the variation factors in the implementation of clinical pathway in ST elevation myocardial infarction，so as to further improve the quality of clinical pathway implementation. Methods：In our hospital from March 2010 to September 2011，clinical path data of 203 cases of acute ST elevation myocardial infarction patients for were analyzed，and correction analysis was con－ducted to the variation analysis interrelated factors. Results：A total of 122 patients with 203 cases did not complete a clinical pathway （60.10%），the patient or family member factors in 114 cases （93.44%），medical personnel factor in 6 cases （4.92%），equipment factors in 2 cases（1.64%），which includes medical cost problems in 45 cases（36.89%），and complications in 42 cases（34.43%）. Conclusion：Clinical pathway variations analysis for STEMI helps to find out the reasons for variation and to reduce variation. Clini－cal pathway can be smoothly fulfilled through timely and effective intervention，and by supplementing and completing the clinical pathway content，so as to improve the treatment and caring quality.