Objective: To research the prevalence of erectile dysfunction(ED)and the influencial factors in male renal transplant recipients(RTR).Methods: A cross-sectional survey was conducted in three renal transplantion centres.Structured questionnaires were administrated by trained interviewers to 824 male renal transplant patients,who had active sexual life in last 6 months.Results: The complaints of ED was reported by 75.5%of the 809 RTR(age range,19-75 y,mean 45±10 y),whose questionnaires were complete fulfillment.Mild,moderate,and sever was 53.6%,8.3%and 13.6%,respectively.The mean age and the graft duration were significantly higher in male RTR with ED compared to potent ones(P=0.000,and 0.04 respectively).Moreover,the severity of ED increased with aging.The percentage of moderate and severe cases of ED increased from 6.7%in patients below 40 y to 28.9%in those over 40 y(P=0.000).The prevalence of ED in the RTR who had no occupation was higher than in those who were holding position(P=0.001).The prevalence of ED decreased with the increase in the education level.The prevalence of ED was 94.3%,86.4%,74.0%and 67.8%in men with elementary school or lower,middle school,high school,and college or higher degrees,respectively(P=0.000).Patients,whose arteria iliaca interna distal end was interrupted,iterative transplantation,worrying transplanted kidney function impacted by sexual life,and with CsA-based immunosuppressive regimens,were more likely to have ED(P=0.000,0.001,0.000,0.000,respectively).There were no statistically significant differences between both groups as regards the incidence of hypertension,diabetes,hyperlipidemia,pretransplant hemodialysis,hemodialysis duration,ligation of spermatic cord,taking Betaloc,and taking Rapamune(Sirolimus).No statistical differences were found in levels of serum creatinine,urea nitrogen,and hemoglobin,between patients with and without ED.Also no statistical differences were found in history of smoking,drinking,smoking consumption,alcohol consumption,between the two patient groups.After Logistic regression analysis,only five factors: age,education level,interruption of arteria iliaca interna distal end,worring transplanted kidney function impacted by sexual life,CsA-based immunosuppressive regimens sustained their significance.Conclusions: Renal transplant has varying effects on erectile function.ED is highly prevalent among RTR,and its influential factors is multiple.Age,education level,interruption of arteria iliaca interna distal end,worring transplanted kidney function impacted by sexual life,CsAbased immunosuppressive,are the main influential factors of ED in male RTR.