Abstract: Objective To deduce the region that the geographical species of Lucilia sericata come from and determine the scene of crime (SOC) based on the gene analysis of mtDNA COⅡ. Methods A 635 bp region for COⅡ of 4 Lucilia sericata (belong to 2 geographical species) were collected and sequenced, compared with the data of GenBank. A neighbour-joining tree with the Tamura and Nei model was constructed by MEGA2.1 package. The number of inherit intervals of inner-species were analyzes by Kimura′s two-parameter model and used for construction the relationships between hereditary and latitude interval by SPSS10.5 soft. Results It showed that they had the relationships between inherit and latitude interval for the 8 geographical species of Lucilia sericata for COⅡ. Conclusion This method can be the evidence deducing the region that the geographical species of Lucilia sericata come from and further to determine the scene of crime (SOC).

Key words: Lucilia sericata, COⅡ, hereditary interval, latitude interval, distributing of geographical species