Abstract： It is an important experimental approach to study syphilis by upbuilding a rabbit model of Treponema pallidum (Tp) infection through inoculation of Tp into the testicles of rabbits. After inoculation, Tp undergoes five stages of evolution, i.e., incubation,exponential growth,stationary phase, retrogression and latency. And, each stage is characterized by the appearance and duration of lesions, features of the parasite, infectivity of the animal's organs, pathological findings, serological changes and correlations of these findings with treatment with penicillin. To establish this model is of great significance for the investigation of pathogenesis, early diagnosis, pharmacotherapy and prognosis of syphilis.