Abstract: Mycoplasma genitalium(Mg)is a common cause of nongonococcal urethritis and cervicitis.Macrolide antibiotics,especially azithromycin,have been used as the first-line therapy for patients with Mg infection.Macrolide-resistant Mg strains have been isolated from some patients with Mg-associated and treatment-resistant non-gonococcal urethritis.It has been revealed that macrolide resistance is mainly associated with mutations in the domainⅤ?of 23S rRNA and in ribosomal protein genes L4 and L22.