Abstract: Fish can obtain important environmental information in the water by perceiving chemicals at minute amounts using their olfactory system, and thereby adjust various life behaviors including predation, courtship, migration and avoiding predators. Fish olfactory neurobehavior is an ideal toxicological endpoint due to its sensitivity to pollutants and ecological importance. Applying fish olfactory neurobehavior to marine ecotoxicology studies will deepen our understanding of the ecological risks of marine pollutants and provide scientific bases for the formulation of marine water quality criteria. This article briefly describes the olfactory system and the molecular neural processes of olfaction in fish and summarizes the current application and prospects of fish olfactory neurobehavior in the field of ecotoxicology.