The estimation size of individual plots the American mink on the res- ervoirs in Saratov region in the period from 2000 to 2014. The average plot size of males – 30.6 hectares, females – 27.8 hectares. During the cold period on most waters plot sizes are increased almost two- fold. Found that females go farther from the center of the rivers and streams than males (females – 203.8 m; males – 166.7 m). American mink is more inclined to the rivers with wide floodplain (?2 = 26.2; p = 0.01).