Abstract: A 36-year-old female received renal transplantation for chronic kidney disease stage 5 in our hospital.On day 9 post-transplantation，she developed fever and presented with pain at her renal graft site.Enterococcus faecalis was detected in the urine.The urine cultures became negative after she was treated with piperacillin sodium and sulbactam Sodium，moxifloxacin，But the patient still had a fever.An abdominal CT scan indicated a perinephric collection on day 17 and a laparotomy was performed to drain the purulent collection on day 18.Four days later,cultures of intraoperative samples from the perinephric exudate showed mycoplasma,which was susceptible to minocycline.Three weeks after the minocycline therapy, symptoms were significant improved.Repeat imaging revealed complete resolution of the perinephric collection.The patient had a good prognosis and no recurrence of symptoms was reported at a 5month followup appointment.Colonization rate of mycoplasma is high in renal transplant recipients.And mycoplasma is the most important pathogen for perinephric infection in these patients，timely monitor is very important for kidney transplant recipients.

Key words: mycoplasma, renal transplant recipientperi, nephric infection