The complete mitochondrial genome sequence of Mesocottus haitej has been obtained by the next generation sequencing, which contained 22 tRNA genes, 13 protein-coding genes, 2 rRNA genes and non-coding control region with the total length of 16,527 bp. The gene content, arrangement, codon usage and base composition of M. haitej mitogenome have no unusual features that distinguish it from most other teleost fishes. According to the result of a pilot phylogenetic analysis, the freshwater Mesocottus is a sister lineage to the Cottus clade. The new mitogenomic data could provide useful information for the further studies on molecular systematics and conservation genetics of cottids.