Objective To understand the causes of high level kinesiophobia in first-episode patients with acute myocardial infarction （AMI）, and to provide reference for exercise rehabilitation intervention for this population. Methods Semi-structured interviews were conducted among 14 first-episode AMI patients with high level kinesiophobia, then the interview data were analyzed using Colaizzi′s seven-step analysis method to extract themes. Results The causes of high level kinesiophobia in first-episode patients with AMI can be summarized into two major themes:individual internal factors and external factors.The former one included five subthemes:insufficient awareness of exercise rehabilitation, avoidance of stress events, negative emotions, over-alertness of one′s own physical state, and low exercise self-efficacy, and the latter one was consisted of three subthemes:lack of family support, inaccurate medical information or guidance, and medical financial burden. Conclusion A variety of factors cause high level kinesiophobia in first-episode patients with AMI. Medical staff should pay attention to early assessment and intervention to improve patients′ cognitive level of exercise rehabilitation, and promote their active participation in rehabilitation exercise training.