Forensic entomology is the study based on the principal of ecological succession of insect’s communities as biological indicators associated with the dead body for calculation of post mortem interval. In the present study, insect fauna identification in dead dog, Canis domesticus L. has been used as in substitute of dead human body in tropical region Mardan, a tool for forensic entomology were carried out in five different decomposition stages, fresh, bloat, active decay, advanced decay and dry. The collected Coleoptera species were Dermestes maculates, Hister sp., Trox sp. and Necrobia rufipes. Dermestes maculates was first arrived to dog carcass while Hister sp. adults and larvae dominated later stages of decomposition. The average temperature (28.3±1.8-40.4±1.7) was found to affect Coleoptera adults, larvae and rate of decomposition of C. domesticus during the observation period for 11 days. This research will be helpful for forensic entomologist for a case study of death to investigate the crimes in district mardan, Pakistan.