Hungry females I. persulcatus (912) from 19 sites of their distribution area (from Estonian SSR, USSR to the Kuril Islands) were measured. The length of the body and that of the dorsal shield reach their maximum in the Primorski Krai, Russian SFSR and in the south of Khabarovsk Krai, Russian SFSR territories. Northwards and westwards and on the islands of the Pacific, ticks are smaller.