Abstract: 【Aim】 The objective of this study is to understand the characteristics of the complete mitochondrial genome of Parnassius nomion and to explore the higherlevel phylogenetic relationships of butterflies based on mitochondrial genome sequences.【Methods】 The PCR amplification technique and Sequencher 4.8 software were used to obtain the whole sequence of mitochondrial genome of P. nomion. Based on the known complete mitochondrial genomes of lepidopteran species, MEGA6.0 software was used to locate and annotate each gene of P. nomion mitochondrial genome. tRNA Scan-SE 1.21 was used to predict the secondary structure of the tRNA genes online. Based on the nucleotide sequences of 13 protein-coding genes of mitochondrial genome, the phylogenetic relationships among 28 butterflies of 10 families (Papilionidae, Parnassiidae, Pieridae, Satyridae, Nymphalidae, Lycaenidae, Danaidae, Acraeidae, Libytheidae and Riodinidae) of Papilionoidea were reconstructed. 【Results】 The results indicated that the complete mitochondrial genome of P. nomion is a circular molecule of 15 362 bp (GenBank accession no.: MF496134), including 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes and an A+T-rich region. The mitochondrial genome of P. nomion is biased toward a high A+T content (79.6%). The relative synonymous codon usage (RSCU) of UUA is the highest in the 13 protein-coding genes in the mitochondrial genome of P. nomion, the relative synonymous codon usage value is 5.08, but AGG and CCG has a relatively low RSCU of 0, which is consistent with the analysis results of Sasakia charonda coreana. All 22 tRNA genes show the classic clover-leaf structure, except that the dihydrouridine (DHU) arm of tRNASer (AGN) forms a simple loop, which is consistent with the secondary structure of tRNA genes in the mitochondrial genomes of other lepidopteran insects. The results of phylogenetic analysis showed that Riodinidae and Lycaenidae are sister groups, Pieridae is closer with the clade of (Lycaenidae+Riodinidae)+(((Nymphalidae+Acraeidae)+Satyridae+Danaidae)+Libyheidae), Parnassiidae is a sister group of Zerynthiinae, and then Parnassiidae+Zerynthiinae is clustered with Papilioninae. P. nomion is closely related with Parnassius epaphus in Parnassiidae. 【Conclusion】 Our study supports that Parnassiidae species should be included in Parnasiinae, Parnasiinae, Zerynthiinae and Papilioninae all belong to Papilionidae, and Parnasiinae and Zerynthiinae are sister groups.

Key words: Lepidoptera, Papilionoidea, Parnassius nomion, mitochondrial genome, phylogeny