Abstract: OBJECTIVE To discuss the clinical effect of Erdi Biejia decoction together with low dose of Tadalafil in treating diabetic erectile dysfunction. METHODS 70 patients with DED were randomly divided into two groups: the control group(35 cases) and the treatment group(35 cases). The treatment group was given Erdi Biejia decoction one dosage every day， orally taken in the morning and evening. Tadalafil pills(5mg) were orally taken once every night for eight weeks. The control group took Tadalafil pills(5mg) once every night for eight weeks. Before and after the treatment， IIEF-5 scores and nocturnal penile tumescence were recorded. RESULTS After the treatment， IIEF-5 scores and nocturnal penile tumescence of both groups significantly improved(P<0.01). After the treatment， the treatment group performed better than the control group(P<0.05). So serious side effects showed in the two groups. CONCLUSION Erdi Biejia decoction together with low dose of Tadalafil were effective in treating DED and were worth of being widely applied in clinical practices.