The characteristic of distribution of Ukrainian lamprey Eudontomyzon mariae in the upper Don basin is presented. The examined part of the basin covers territories of Kursk, Orel, Tula, Ryazan, Lipetsk, Tambov, and Voronezh oblasts. It is shown that, at the present time in the upper Don basin, restoration of the range and an increase in the numbers of Ukrainian lamprey is occurring. The main concentrations of the spe cies were recorded in the Don and Krasivaya Mecha rivers and their tributaries. In the basin of the Sosna River-one of the largest tributaries of the Don-Ukrainian lamprey is very widely distributed, but its pop ulation remains small and rarified. To preserve the species in the upper Don basin, it is suggested-in addition to already existing specially protected natural territories-to organize new ones in some small rivers and in the upper reaches of the Krasivaya Mecha River. In case of emergence of technogenic catastrophes, they can serve as donors for the entire basin of the upper Don. rivers in Tula oblast were examined (the Don River with its tributaries of the first order, Krasivaya Mecha River with tributaries) and 16 rivers in Lipetsk oblast (Don with tributaries Vya zovka, Sukhaya Lubna, and Kamenka, Sosna with Vorgol tributary, Voronezh with tributaries Studenka, Kuzminka, Delekhovka, Ranova with Sukhaya Kobelsha tributary, and Khamelinka, Ptan, Plavutka, Yagodnaya Ryasa). In 2012, 21 rivers of the Sosna basin over the territory of Orel, Kursk, and Lipetsk oblasts were examined. To characterize distribution of Ukrainian lamprey, all data on catches of larval lam prey obtained by the authors during catching fish using fry drag seine (mesh of 6.5 mm) in 2010-2012, as well as data on distribution over the period from 1987, were used (Sarycheva and Sarychev