The state of the Natrix natrix population in the protected area of the Mytishchi Forest Park and the recreational zone of the Losinoostrovsky Forest Park of the National Park “Losiny Ostrov” was studied. In the Mytishchi forest park, the share of snakes was 63% of the total, in the Losinoostrovsky forest park – 37%. At the same time, the largest number of snakes is observed in recreational areas of Mytishchi Forest Park (37%) and Losinoostrovsky Forest Park (38%). The maximum density of snakes was 56 ind./ha also in recreational area of Losinoostrovsky Forest Park. There were two peaks in abundance during the field season in May-June and late August – September. The decline in numbers occurs in July, when the number ranged from 0 to 4 ind./ha. It was found that the sex composition of males and females is in the ratio of 1 : 1 in each study area. Most individuals were found with a length of 31–70 cm – 36%, and the least number of individuals longer than the norm of 100 cm – 10%. The grass snake population on the territory of the Losiny Ostrov National Park feels safe both in protected natural areas and in recreational areas with a moderately increased anthropogenic factor.