Abstract: 【Aim】 To explore the phylogenetic relationships within and between three major subfamilies (Polyommatinae, Theclinae and Lycaeninae) of the Chinese lycaenids based on the mitochondrial gene sequence data. 【Methods】 The partial mitochondrial  COI and Cytb genes of 53 species were amplified and determined with PCR method, the sequence variation of these species were also analyzed, and the phylogenetic trees of these lycaenid species were reconstructed with maximum-likelihood (ML) and Bayesian-inference (BI) methods. 【Results】 The results of the sequence analysis showed that the two combined genes are 1 431 bp in length, including 855 conserved sites, 576 variable sites and 488 parsimonious-informative sites, and the average percentage of A+T is 74.5%, which is much higher than that of G+C (25.5%). The results of phylogenetic analyses indicated that the Polyommatinae and Lycaeninae were monophyletic groups, whereas the Theclinae was a paraphyletic group. All the taxa in this study contained three main clades: the first was the subfamily Lycaeninae, the second was the subfamily Polyommatinae plus the tribes Hypolycaenini and Aphnaeini of the subfamily Theclinae, and the third was the other four tribes of the subfamily Theclinae, with their relationship as (((Theclini+Arhopalini)+Deudorigini)+Eumaeini). 【Conclusion】 The subfamily Lycaeninae is a monophyletic group, while the Polyommatinae and Theclinae are more closely to each other, with the relationship of their main groups awaiting further investigation.

Key words: Lepidoptera, Lycaenidae, COI, Cytb, phylogeny, China