Abstract: Pigmentation is an adaptive mechanism for UV irradiation.Skin can keep from UV irradiating through pigmentation with several internal and external factors.UVB is the most important factor of pigmentation.Our body regulates molecules of pigmentation with a complex network system in UV irradiating with 125genes involved.In the past 10 years, we have known that exploration of mechanism of UVB-induced pigmentation is important, because the incidence of UV-induced disease is increasing and skin whitening is more and more popular.This article lists some molecules involved in UVB-induced pigmentation, such as microRNA, MC1R, p38 MAPK, paracrine factor, Ucn1 and hemidesmosome, and demonstrates their specific mechanism.