A new species of anoplocephalidean cestode Paranoplocephala longivaginata sp. n. from some rodents (Clethrionomys rutilus, Sciurus vulgaris) of the Western Siberia is described. The new species differs from formerly known species of the genus Paranoplocephala by a structure of copulatory organs: the length of cirrus and the length of vagina exceed the length of genital bursa more than 1.5 times; the internal surface of the vagina is covered with hair-like bristles along all its length.