The aims of this research are to determine the abundance of microplastics and macroplastics in the Klang River basin (namely the Klang River and Kerayong River) in relation to water quality status and determine the relationship between the abundance of microplastics and microplastics, water quality (marine, estuarine, freshwater, highly urbanize area) and other environmental data. In addition, it correlates statistical and hydraulic data with abundance of macroplastics.