【Background】The tomato leafminer Tuta absoluta (Meyrick), native to South America, is one of the most devastating and invasive pest species worldwide. Morphological identification of T.absolutais limited by small size, the high degree of similarity and polymorphism. 【Method】In this study, a method was described for the development of DNA marker for identification of T.absoluta. One pair of speciesspecific PCR primers (SS-COⅠ) based on a fragment of known mitochondrial DNA cytochrome oxidase I (mtDNA COⅠ) sequence was designed for T.absoluta. The specificity of the primer pair was validated using six other leafminer species, including Liriomyza sativae Blanchard, L.huidobrensis(Blanchard), L.trifolli (Brugess), L.chinensis(Kato), Phytomyza horticola Goureau and Lyonetia clerkella L., all of them commonly occurring in China. 【Result】All T.absoluta specimens were detected, and no cross reactions with other leafminer species were observed. The method was tested on single egg and adult debris (including antenna, head, thorax, abdomen, wing, leg) of T.absoluta, and proved to be applicable. Even at the concentration of 312.5 pg·μL-1 DNA, the target fragment could be detected in all replicates. 【Conclusion and significance】The technique developed here should be useful in quarantine at ports of entry and in guarantee the safety of agricultural production and ecological environment in China.