IPL technology has long been proved clinically to be significantly effective treatment for acnes. Acne vulgaris is a common disease in various ages and it is a chronic inflammatory disease of the pilosebaceous units. The sebum in the pilosebaceous units attracts P. acnes(Propionibacterium acnes) and plays important role in mediating follicular inflammation. The blue light where its wavelengths(400 ~ 700 nm) are part of total wavelength spectrum of IPL causes the formation of reactive oxygen species through the excitation of porphyrins produced by P. acnes and injury to the surrounding areas in the sebaceous glands. And also, mixed blue and red light, longer wavelength (870 ~ 1200 nm) in IPL, has been demonstrated to be a more effective means of treating acne than blue light alone.