The cardiac sudden death occupies primacy among the cause of death in adult. Myocardial infarction is one of the main mechanisms of sudden death of coronary heart disease. Because of early myocardial infarction happened abruptly and might die in a short time, and the typical or special changes in morphology is absent, so it is the focus of medico legal research forensic fulfill all long. This paper reviewed the characters of myocardial infarction, applications and limits in forensic fields, and prospected feasibility of new clinical markers in forensic practice, and expected to enhance accuracy of postmortem diagnosis in MI.