Objective: To establish the profile of erectile dysfunction in different age groups,and analysis the effect of sildenafil based on age stratification.Subjects and Methods: From 2007 to 2008,a total of 4,507 men diagnosed with erectile dysfunction(ED)were enrolled from 46 centers in China;4,039 of these patents were treated with sildenafil and asked to complete the Erectile Function domain of the International Index of Erectile Function,Erection Hardness Score,and Quality of Erection Questionnaire.The patients were divided into 5 groups on the basis of their age [group A: 20-30 years(yrs);group B: 31-40 yrs;group C: 41-50 yrs;group D: 51-60 yrs;and group E: >60 yrs].Results: The patients with ED over 30 yrs old,with the increase of age,both scores of IIEF-EF and EHS tended to decrease.Decrease of erectile function and erectile hardness scores were statistically significant between the patients aged over and below 50 yrs,and the conditions were even worse in the patients over 60 yrs.After comparing pre and post treatment IIEF-EF questionnaires,EHS,and IIEF Q13("How satisfied have you been with your overall sex life?"),we discovered that the aging males had worse erectile function,erection hardness,and sexual satisfaction than the younger males(P<0.001).After treatment,the improvement rates in the IIEF-EF,EHS,and IIEF Q13 scores were 107.0%,83.1%,and 116.5%,respectively.The magnitude of these changes demonstrated significant differences among groups(P<0.001).Accordingly,aging males(>50 years)are likely to benefit more from medical treatment.Conclusions: Our data suggested that for men below 50 yrs old,prevention and treatment of ED were essential;while for those over 50 yrs old,the treatment of ED and the prevention of its comorbidities were highly recommended.The aging males should be informed that age is not a limiting factor for medical ED management,and it is never too late to treat.