摘要:The Citarum River is one of the most polluted rivers in the world because of the inadequate waste management system and community ignorance. Plastic is one of the contaminants in the Citarum watershed. In general, plastics less than 5 mm in size are defined as microplastics. Microplastics are persistent and harm the environment. This article aims to determine the potential for pollution and distribution of microplastics in freshwater systems, especially in the Citarum watershed area. Using a combination of literature study methods with Geographical Information Systems (GIS) analysis, this article explains that microplastic contamination has occurred along the Citarum watershed from upstream to downstream, found in water and sediment and fish samples. Facilitated by their small size and high stability in the environment, microplastics can move from the aquatic environment into the food chain and cause longterm damage. This case causes a severe threat to the quality of freshwater in the Citarum watershed. Therefore, this article can be used as a reference for managing pollution in the Citarum watershed area.