Myopia is the most important cause of visual impairment in adolescents. However, its etiology is complex. In recent years, a large number of epidemiological studies have been done on risk factors of myopia. Most of these studies is cross-sectional study, not longitudinal cohort study. Overall, the incidence of myopia is the result of the interaction between genetic susceptibility and environmental exposure. This review is about the risk factors for myopia.