[Objective] The distribution and sources of microplastic pollution in the Nanfei River as it flows through cities were studied in order to not only accumulate basic data for microplastic pollution prevention, but also provide a scientific basis for the control and treatment of microplastics.[Methods] The water and sediment samples from the Nanfei River, located in Hefei City, Anhui Province, were collected during March 2019, and the distribution and sources of microplastics in these samples were studied by density flotation, stereomicroscope identification, and Fourier infrared spectroscopy.[Results] Four types of microplastic particles (foams, fibers, particles, and fragments) were common in the water and sediment samples from the Nanfei River. The abundance distribution was basically similar for all types of microplastics, with all types more concentrated in the densely populated middle reaches of the river, indicating that microplastic pollution in the river was greatly affected by human activities. The particle size distribution of microplastics in the water and sediment samples showed that the abundance of microplastics decreased as the particle size increased. Fiber microplastics accounted for the largest proportion of microplastics observed, and foam microplastics accounted for the least, indicating that the microplastics were mainly derived from people's daily domestic activities and sewage treatment plant discharges. Regarding the color of the microplastics, the largest proportion of microplastics were colored or transparent, whereas black and white microplastics accounted for less. In contrast to sediments, the abundance of microplastic fragments was higher than that of microplastic particles in the water samples. The results of the Fourier infrared spectrometry showed that the particle and fiber microplastics were polyethylene, the fragments were polypropylene, and the foam microplastics were polystyrene.[Conclusion] Microplastics were widespread in river water and sediments at high levels, and were mainly derived from people's daily activities and discharges from sewage treatment plants.