Abstract: The aim of this article was to research wether AIDS patients and HIV-infected individuals in our country contained mycoplasma penetrans (Mpe)、mycoplasma fermentans (Mf) and mycoplasma pirum (Mpi) infections. We cultured throat swabs and urine samples with the modified SP-4 culture medium for isolation. The positive culture was identificated with MIT and PCR. We isolated one Mpe strain from the urine of 2 AIDS patients and one Mf strain from the urine of 7 HIV-infected individuals. We were the first one to prove pathogenically that Mpe and Mf infections existed in AIDS patients and HIV- infected individuals in Jiangsu province,and it was necessary to pay attention to Mpe and Mf infections in AIDS patients.