Abstract: The sequencing strategies and analysis results of 40 complete mitochondrial genomes from Orthoptera were summarized. The most important findings include: （1） three types of gene order in Orthoptera were found. The gene order of Erianthus versicolor is the same as that of Ensifera species, and the gene order of tRNA^Glu, tRNA^Ser and tRNA^Asn in Teleogryllus emma （Gryllidae） are located in the minor strand. （2） The mitochondrial DNA of Ruspolia dubia contains a short A+T-rich region with 70 bp in length. （3） The conserved consensus structures of A+T-rich region were determined. The Z-curve method was applied to analyze the A+T-rich region, and the results showed that signals similar to prokaryote duplication origin exist in A+T-rich region. （4） The secondary structures of 16S sRNA and 12S rRNA from 30 species were predicted and compared with those of other insects. Some tRNA-like or tRNA isotype structures were found in noncoding regions of mitochondrial genomes of Orthoptera. （5） The phylogenetic relationships at families and superfamilies of Orthoptera were reconstructed based on the data of the 40 complete mitochondrial genomes.

Key words: Orthoptera, mitochondrial genome, evolution, phylogenomics, phylogeny