Microbial keratitis is one of major causes of vision loss and blindness worldwide today,especially in developing countries in Asia and Africa.Population-based annual incidence of microbial keratitis is 0.36/10000 to 79.9 /104.The epidemiological features and predisposing factors for microbial keratitis varies significantly from country to country,even from region to region within the same country.The progress of research on describing epidemiological characteristics demographic characteristics and predisposing factors of microbial keratitis were reviewed in this paper.