Abstract: Objective To discuss the method of reducing error in estimating postmortem interval （PMI）. Methods Two hundred and fifty-six solved murder cases from 2003 January to 2013 January in Changzhou and Nanjing City were collected, The PMI of all cases was estimated by traditional method and then compared with the real PMI obtained after the cases were solved. The cases were grouped according to the PMI, the accuracy was calculated, and the reasons of suboptimal PMI were analyzed. Results The accuracies of early PMI （less than 12 h and 13-24 h） were 90% and 89%, respectively; while the accuracies of late PMI （1-7 d, 1-2 weeks, 3-4 weeks, 1-6 months, 7-12 months and 1-5 years） decreased over time, being 79%, 76%, 83%, 79%, 60% and 50%, respectively. The common reasons of estimating error included improper inference methods, water submerged body, extreme temperature, lack of objective evidence, intentionally abandoned body, and changed or destroyed scene, etc. Conclusion The multiple index data can reduce the error in estimating PMI.

Key words: forensic pathology, postmortem interval, homicide