﻿AbstractMitochondrial genome analysis is an important tool for studying insect phylogenetics. The longhorn beetle,Batocerahorsfieldi, is a significant pest in timber, economic and protection forests. This study determined the mitochondrial genome ofB.horsfieldiand compared it with the mitochondrial genomes of otherCerambycidaewith the aim of exploring the phylogenetic status of the pest and the evolutionary relationships among someCerambycidaesubgroups. The complete mitochondrial genome ofB.horsfieldiwas sequenced by the Illumina HiSeq platform. The mitochondrial genome was aligned and compared with the existing mitochondrial genomes ofBatoceralineolataandB.rubusin GenBank (MF521888,MW629558,OM161963, respectively). The secondary structure of transfer RNA (tRNA) was predicted using tRNAScan-SE server v.1.21 and MITOS WebSever. Thirteen protein-coding genes (PCGs) and two ribosomal RNA gene sequences of 21 longhorn beetles, includingB.horsfieldi, plus two outgroups,Dryopsernesti(Dryopidae) andHeterocerusparallelus(Heteroceridae), were analyzed. The phylogenetic tree was constructed using maximum likelihood and Bayesian inference methods. In this study, we successfully obtained the complete mitochondrial genome ofB.horsfieldifor the first time, which is 15 425 bp in length. It contains 37 genes and an A + T-rich region, arranged in the same order as the recognized ancestor of longhorn beetles. The genome ofB.horsfieldiis composed of 33.12% A bases, 41.64% T bases, 12.08% C bases, and 13.16% G bases. The structure, nucleotide composition, and codon usage of the new mitochondrial genome are not significantly different from other longhorn mitochondrial genomes. Phylogenetic analyses revealed thatCerambycidaeformed a highly supported single clade, andVesperidaewas either clustered withCerambycidaeor formed a separate clade. Interestingly,B.horsfieldi,B.rubusandB.lineolatawere clustered withMonochamusandAnoplophoraspecies in both analyses, with high node support. Additionally, theVesperidaeSpiniphilusspinicornisandVesperussanziand the 19Cerambycidaespecies formed a sister clade in the Bayesian analysis. Our results have produced new complete mitogenomic data, which will provide information for future phylogenetic and taxonomic research, and provide a foundation for future relevant research.