Abstract: Objective To study the situation of mycoplasma pneumoniae (Mpn) in lesions of STD patients in China. Methods Nested PCR (Npcr) and DNA sequence determination were applied to test the samples of urethra swab/vaginal swab and the Mpn culture to some Npcr positive patients was done. Results 74 cases of 786 STD patients were positive for Mpn by Npcr, the positive rate was 9.4% of 484 male patients, positive rate was 10.5% of 302 female patients, positive rate was 7.6% . There was no significant difference between them (P>0.05).Mpn positive patients were present in both male and female STD cases. Of 12 cases of Mpn positive samples by Npcr,4 cases of Mpn first generation culture were positive,one of them passed to the nesxt generation successfully. DNA se-quence determination was carried out to the Npcr product of one swab sample and noe Mpn cultural isodated sample.The determined sequence was identical with typical Mpn strain. Conclusions In China, Mpn are present in lesions both male and female STD patients.