There is a high potential of microplastics accumulation in the Arctic, namely in the Barents Sea region [Cozar et al., 2017]. The Russian Arctic is a poorly explored region, but due to climate changes and the North Passage (NP) opening the anthropogenic load on this area has been increasing. There is also a lack of methods for environmental monitoring of the Arctic seas. The main purpose of this study was to carry out a first ever survey of all Russian Seas along the North Passage and to develop a sampling technique for microplastic particles content in the surface water layer for the Arctic Seas characterized by very high productivity. Over 120 water samples were taken during the Program “TRANSARCTICA-2019” in the summer 2019 (July – September). Water from the subsurface layer (4 m) was sampled using shipboard pump and then filtered through a special filtering instrument with metal mesh (100 μm). Samples were fixed and treated in laboratory according to the methodology [Zobkov et al., 2018], including organic material digestion, visual quantification of microplastic particles with microscope and spectroscopic analysis. The work was supported by the Ministry of Science and Education of RF, project № FSZU-2020-0009. 14 samples were processed for preliminary assessment of microplastic contamination of all 7 seas along the NP. Average microplastic particles content was 0.03 particles/l. The results of the study showed the relationship between the nature of pollution and the remoteness of the sea from large cities. Seas that have a large transport load are characterized by only higher concentrations, but also by a certain type of microplastics. The highest concentration of microplastics was noted in the Sea of Okhotsk and the Barents Sea, and the lowest - in the East-Siberian Sea, and was 0.357 and 0.001 particles per l, respectively.