Department of Eastern Siberia (about 42 thousand herbarium sheets) began to fill out in 1930 with the first expedition of P.N. Krylov and L.P. Sergiyevskaya to Transbaikalia and was especially extended as a result of the next 30 expeditions of L.P. Sergiyevskaya. L.I. Obolentsev, T.P. Berezovskaya, L.I. Potekhina, S.V. Gudoshnikov, V.N. Siplivinsky also collected materials in Eastern Siberia. G.P. Sumnevich gathered a beautiful collection and a significant amount of materials was received from expeditions of A.V. Kuminova, L.I. Malysheva and G.A. Peshkova. Valuable materials ware brought from the Transbaikalia in 70-80s from expeditions of V.I. Kurbatskaya with students and postgraduates I.I. Gureyeva and M.V. Olonovoa.