The technology of color Doppler ultrasonography (CDU) was more and more popularly applied to the clinical diagnosis of erectile dysfunction (ED) in recent years since its introduction into this domain by Lue et al. CDU is preferable as a diagnostic means for its advantages of being convenient, non-impairing and easily repeatable. Nowadays, CDU is becoming a hotpoint of research. However, CDU still has some defects that have limited its application. This article reviews its mechanism, usage, research development and application combined with other diagnostic means, and introduces a new type of power-Doppler imaging.