Abstract: Ye Xingdong, Gao Fangming, Cao Wenling, Lin Hongda, Ren Zefang Guangzhou Institute of Dermatology, Guangzhou 510095, China （Ye XD, Gao FM, Cao WL）; School of Public Health, Sun Yat?sen University, Guangzhou 510080, China （Lin HD, Ren ZF） Corresponding author: Ye Xingdong, Email: yxingdong@qq.com 【Abstract】 Objective To investigate the feasibility and prospects of nested real?time PCR （NR?PCR） technique for Treponema palladium （Tp） detection in various samples of different stages of syphilis from patients preliminarily diagnosed as syphilis. Methods Targeting the Tp polA gene, NR?PCR was performed to detect Tp DNA in various samples from the patients with various stages of syphilis at the first clinic visit, including skin tissue fluid swabs, serum, whole blood, cerebrospinal fluid （CSF） and earlobe blood. Data were analyzed with SPSS software version 13. Results A total of 368 clinical samples were collected from 200 patients with syphilis. With a detection limit of 2 Tp/ml, NR?PCR showed that the total positive rate for Tp DNA was 71.7% （264/368）. The Tp DNA positive rate was highest in earlobe blood samples （92.0%, 23/25）, followed by CSF samples （90.2%, 46/51）, skin tissue fluid swabs （74.3%, 26/35）, serum samples （66.9%, 99/148） and whole blood samples （64.2%, 70/109）. There was good agreement between NR?PCR results and serologic test results, with a consistency rate of 76.0% （152/200）. Furthermore, the Tp DNA positive rate did not differ between patients with primary （12/19） and secondary syphilis （14/16） in skin tissue fluid swabs （χ2 = 2.62, P > 0.05）, and was slightly but insignificantly higher in patients with secondary syphilis than those with primary syphilis in the serum samples （χ2 = 3.6, P = 0.06）. The Tp DNA positive rate of whole blood samples was also higher in patients with secondary syphilis than those with any other types of syphilis. Among patients with neurosyphilis, no significant difference was observed in the Tp DNA positive rate between earlobe blood samples and CSF samples （P = 0.06）. Among patients with latent syphilis, the Tp DNA positive rate was significantly higher in serum samples with an RPR titer of ≥ 1∶8 than those with an RPR titer of ≤ 1∶4. Conclusion NR?PCR is feasible for detecting Tp DNA in various kinds of samples, and the Tp DNA positive rate is influenced by stages of syphilis and types of samples, as well as RPR titers.