Sillago japonica(Perciformes,Sillaginidae),known as a small to moderate-sized fish,is a popular food fish and highly valued species in the South and East China.However,the phylogenetic relationship of S.japonica is controversial between several morphological and molecular studies.The complete mitochondrial genome of S.japonica was expected to contribute new insights into the taxonomy and molecular phylogenetic relationship of this species.Therefore,the complete mitogenome of S.japonica collected from Zhanjiang Harbor was determined through the high-throughput DNA sequencing technology.The circular mtDNA molecule of S.japonica was 16 645 bp in size and encoded 13 protein-coding genes,22 tRNAs,2 rRNAs(12S rRNA and 16S rRNA)and 2 non-coding regions [a light-strand(L-strand)replication origin(OL)and a control region(D-loop)],with the gene arrangement and content identical to other typical vertebrate mitogenomes.The D-loop located between tRNAPro and tRNAPhe and contained termination sequence domain(TAS),central conserved block(CSB-F,CSB-E,CSB-D,CSB-C and CSB-A)and conserved sequence block(CSB-1,CSB-2 and CSB-3).The identity analysis revealed that the mitogenome sequence of S.japonica shared a relatively high sequence identity to S.asiatica(81.5%)compared with S.aeolus(77.5%),S.indica(77.1%),and S.sihama(76.3%).The neighbor-joining tree of complete mitogenome sequence showed that S.japonica firstly clustered together with S.asiatica,then grouped with S.indica and S.sihama,and finally gathered with S.aeolus.Taken together,the results absolutely supported the evolutionary position of S.japonica and provided new insights into phylogenetic relationships of Sillago.