To investigate the behavior changes of rats after myocardial infarction，so as to provide animal models for studying the mechanism of depression after myocardial infarction and the treatment medicine. Methods：The rats were given thoracotomy and left front descending coronary artery ligation while sham ligation control rats received thoracotomy without ligation. Sucrose water consumption test and open-field test were evaluated 4 weeks after surgical operation. Results：The score of horizontal movement，vertical movement and the consumption of sucrose were significantly decreased (P<0.05 or P<0.01).Conclusion：After myocardial infarction，the rats decrease activity，lose interests in new environment and lack pleasure，all of which indicate the symptoms of depression. They can be ideal animal models for further study on depression after myocardial infarction.