The paper is devoted for origin of microplastics in aquatic environment and possible methods of characterization and analysis. According to US National Oceanic and Atmospheric Administration, microplastics are synthetic organic polymer particles with a size less than 5 mm. Microplastics pollution is a significant ecological problem in the world. A lot of surface waters are significantly polluted by various types of microplastics. These pollutants were found in rivers, lakes, oceans, sediments, wastewater, drinking water and bottled water. But in Ukraine microplastic problem of surface water do not meet the interest of scientists and ecological organizations. Disintegration of plastic waste is one of the main sources of microplastics in water. But there are a lot of other sources of primary and secondary microplastics, including components personal care products, industrial abrasives, abrasion from car tires, paint failure, industrial processes, textile washing, at-sea losses, etc. Microplastics can harm ecosystems and cause many health problems for different organisms, including problems with feeding and digestion, endocrine disruptions and changes in cellular functions. In general, health effects and environmental impacts are dependent on the size of the microplastic particles and chemical structure of these polymers. Thus, it is very important to understand chemical composition, physical forms, transport in environment and fragmentation of microplastics due to the need to predict possible exposure effects. There are a lot of methods for characterization and analysis of microplastics, but all of them have some disadvantages. Microplastics determination is often especially difficult for water with low microplastics content due to very large volumes of water samples and very small mass of separated plastics.