Abstract: Alcohol is one of the most commonly substance in body fluids in investigations of unnatural deaths and in forensic cases,he forensic toxicologist needs to determine whether the alcohol positive source was ingested before death or decomposed in postmortem.Therefore,for the toxicological analysis of ethanol in postmortem,it is very important to select appropriate biological samples，appropriate preservation methods and instrumental analysis methods. On the basis of consulting a large number of literatures，this paper reviews the mechanism of ethanol production in postmortem specimens,reasonable selection and preservation of biological samples,and instrumental analysis methods for ethanol detection in postmortem. It provides certain reference and basis for the related cases of post-mortem ethanol testing in the field of forensic science.