The frequent use of pesticides promotes the agricultural economy, but also brings a lot of environmental problems. When entering the environment from agricultural activities, pesticides can migrate and transform in different ways, finally sank into the lake by runoff, damaging ecological environment and affecting human health. Therefore, it is necessary to study the distribution and fate of pesticides in lake watershed ecosystem. Fugacity-based fate models could provide an effective approach of transportation behavior and fate of pesticides in environmental. The concept of "fugacity" is used to describe the chemical activity of pollutants between different environmental media, so that the simulation results are based on physicochemical properties of chemicals and environmental system. Fugacity models can not only predict residual levels of pesticides in various environmental media, but also reveal spatial distribution features, and will be an important tool for lake watershed ecosystem management. This article reviews its theoretical basis and introduces development status of fugacity models in recent years, and analyses their application in pesticides research and lake watershed ecosystem management, then puts forward the application prospect of the fugacity models in pesticides research. The studies would provide scientific and technical supports in pesticides control and management.