Abstract: 【Aim】 To sequence and analyze the complete mitochondrial genomes (mtgenomes) of Caerulea coeligena and Dodona maculosa, and to explore the phylogenetic relationships in Papilionoidea based on the known mitochondrial genome data. 【Methods】 The complete mtgenomes of C. coeligena and D. maculosa were sequenced using Illumina NovaSeq 6000 sequencing platform, assembled and annotated, and the secondary structure of tRNA genes was predicted. Based on the nucleotide sequences of 13 protein-coding genes (PCGs) from the mtgenomes of 48 reported butterfly species belonging to six families in Papilionoidea obtained from the NCBI database, the selective pressures on these 13 PCGs in 50 species were analyzed. The phylogenetic relationships among these 50 species, as well as their respective families and subfamilies, were analyzed using maximum likelihood (ML) and Bayesian inference (BI) methods. 【Results】 The mtgenomes of C. coeligena and D. maculosa (GenBank accession numbers are MZ489120 and MZ 489121, respectively) are 15 164 and 15 486 bp in length, respectively. Their genome size, structure and composition, gene arrangement, nucleotide composition, codon usage, and predicted tRNA structure of mitogenomes of C. coeligena and D. maculosa were similar to those of the known closely related butterfly species. The mtgenomes in Papilionoidea exhibited a high level of purifying selection, with the ratios of nonsynonymous substitution rate to synonymous substitution rate (K_a/K_s) for the 13 PCGs obviously lower than 1. The phylogenetic relationships in Papilionoidea were (Papilionidae+Hesperiidae+Pieridae+(Nymphalidae+ (Lycaenidae+Riodinidae))).【Conclusion】 The reconstructed phylogenetic tree based on the mtgenomes of 48 reported butterfly species in Papilionoidea and two newly sequenced species in this study suggests that Riodinidae and Lycaenidae be monophyletic， and sister each other. The sister group would be closely related to Nymphalidae in phylogenetics. Moreover, Papilionidae may represent one of the earliest lineages in Papilionoidea. This study provides new molecular data to support further research on the systematic evolution and refinement of the classification system for butterflies.

Key words: Caerulea coeligena, Dodona maculosa, Papilionoidea, mitochondrial genome, phylogeny