The complete sequences of mitochondrial coⅠ genes of Limnonectes kuhlii and Limnonectes fragilis were amplified and sequenced using PCR technique

and then analyzed through several biologic softwares.When Sphenodon punctatus（AF534390） and Alligator mississippiensis（Y13113）were selected as outgroups

we aligned them with the same mtDNA fragments of 22 other frogs recorded in the GenBank

and reconstructed phylogenetic trees using MEGA version 3.1

based on the nucleotides sequences（1st+2nd codon positions） and the amino acid sequences data

respectively.Neighbor-joining（NJ） and Maximum Parsimony（MP） analyses generated nearly identical tree topologies.The results were revealed: The species examined in this study were clusterd into two clades.The first clade included 5 families of Archaeobatrachia（9 Species

including Pelobatidae and Pipidae）

and the second clade included 5 families of Neobatrachia（15 Species）.The results supported the monophyly of each of the two suborders（Archaeobatrachia and Neobatrachia）.A close relationship between Discoglossidae and Bombinatoridae was showed within Archaeobatrachia.There were two pairs of taxa cluster: Bufonidae + Hylidae and Ranidae + Rhacophoridae in Neobatrachia.Two trees strongly supported a sister group relationship for 3 species of Limnonectes（L.fujianensis

L.kuhlii and L.fragilis） and Fejervarya（F.limnocharis）

and favored a L.fujianensis + L.kuhlii clade to exclusion of L.fragilis.