EN
The paper deals with the theoretical basis, methods and the main results of the investigations of the river system structure (the network of rivers of different orders) transformation. On the basis of a morphometrical analysis of topographical maps from different periods (1855, 1935, 1975, 2005) in the 1:100 000 scale, using the Strahler-Filosofov classification scheme, the structure of representative river systems of Ukrainian Carpathians was investigated. The partial and the total length and number of the streams of every order as well as the correlation between these parameters and bifurcation coefficients were determined. The trends and scales of the river systems structure transformation for the period 1855-2005 were also evaluated. Subject to investigation were the river systems of NE macroslopes of the Carpathlian Mountains.