Abstract: Objective:To explore relationship between the redox reaction and male patients with type 2 diabetes erectile dysfunction(DED) to provide the new reference in the diagnosis and treatment of DED.Methods:Sixty middle-aged men were divided into the control group,type 2 diabetes non-erectile dysfunction(NED group) and type 2 diabetes erectile dysfunction group(DED group)(20 cases each group).The serum levels of peroxidation product 4-hydroxynonenal(4-HNE),Malonaldehyde(MDA) and Nitric oxide(NO) were detected,the relationship between peroxidation and DED was identified.Results:The body mass index(BMI) and Glycated hemoglobin(HbA1c) in DED group were significantly higher than those in NED group and control group(P<0.01),the HbA1c level in NED group was significantly higher than that in control group(P<0.01).The total testosterone and IIEF-5 in DED group were significantly less than those in NED group and control group(P<0.01),the total testosterone level in NED group was significantly less than that in control group(P<0.01).The serum levels of 4-HNE and MDA in DED group were significantly higher than those in NED group and control group(P<0.01),the MDA level in NED group was higher than that in control group(P<0.05).The serum level of NO in DED group was significantly less than that in NED group and control group(P<0.01),the serum level of NO in NED group was significantly less than that in control group(P<0.01).Conclusions:Redox reaction play a promotion role in the development and occurrence of DED by the penile vascular endothelial injury mediated by NO.