Résumé
It is difficult to estimate PMI of whom died long times ago, because corpse goes by many decomposition stages. So it makes investigation more difficult. Nowadays many studies about PMI estimation have been performed. In other countries, forensic entomology studies which is possible to estimate not characteristic of death site but also exact death time are actively advanced. So forensic entomology has been more important related not PMI estimation but also many lawsuits in other countries. In Korea, the necessity of Forensic entomology has increased after occuring of the case 'Gaeguri Sonyeon(missing boys who went to catch a flog)'. In this case, regional characteristic is known by insects found on the corpse or clothes. We suggest possibility of applying forensic entomology, consideration, some limitations and the direction of the future study through the analysis, comparison with true facts, and PMI estimation using collected fly larvae in "Hwaseong Case".