[目的]克隆并分析二化螟线粒体细胞色素c氧化酶亚基I基因(cox1)。[方法]利用PCR方法扩增了二化螟线粒体cox1基因,并测定了其全序列。通过检索GenBank数据库获得了其他21种鳞翅目昆虫的cox1序列,并进行了同源性比较和分子系统学分析。[结果]cox1基因编码框包含1531个核苷酸,编码510个氨基酸的蛋白;起始密码子为CGA,终止密码子仅由一个T组成。利用ML方法构建了基于cox1基因编码氨基酸序列的鳞翅目昆虫的分子系统树,发现分子系统树与从形态学角度的系统分类在大方面上是基本一致的,但也略有差异。[结论]为进一步研究cox1基因的表达和应用奠定了基础 [Objective] The research aimed to clone and analyze mitochondrial mitochondrial cytochrome c oxidase subunit I gene (cox1) of rice borer. [Method] The mitochondrial COX1 gene of Chilo suppressalis (Chilo suppressalis) was amplified by PCR and sequenced. The cox1 sequences of 21 other Lepidoptera insects were obtained by searching the GenBank database and homology comparison and molecular phylogenetic analysis were performed. [Result] The coding region of cox1 gene contained 1531 nucleotides and encoded a protein of 510 amino acids. The initiation codon was CGA, and the stop codon consisted of only one T. The molecular phylogenetic tree of lepidopteran insects based on the amino acid sequence of cox1 gene was constructed by using ML method. It was found that the molecular phylogenetic tree was broadly consistent with the systematic classification from the morphological point of view, but it was also slightly different. [Conclusion] The study laid the foundation for further study on the expression and application of cox1 gene