Abstract:Objective To identify the 17 helicobacter isolates isolated from laboratory rodent animals to obtain a strain which possesses typical biological and genetical characteristics as a type strain.Methods To identify the isolates to species level by means of biological characteristics,16S rRNA sequence analysis,phylogenetic tree and ultrastructure analysis.Results the isolates can be classified into two species: one was Helicobacter bilis,another was Helicobacter sp. Conclusions the isolates are Helicobacter bilis and Helicobacter sp.not identified at species level.The 16S rRNA sequences of Helicobacter bilis has 99.6% similarity to the type strain ATCC 51630.Helicobacter bilis can be used as a type strain for surveillance.