The compatibility assessment of the global state reference frame PZ-90 with the International terrestrial reference frame (ITRF) was performed based on: 1) analysis of the obtained transformations parameters of both reference frames; 2) comparison of GLONASS orbits that were determined from ground stations specified in two reference frames. Root of the Sum of the Squares (RSS7) was used as a consistency characteristic of two reference frames. RSS was calculated as the square root of the sum of the squares of seven transformation elements (the Helmert parameters), the angular elements and the scale factor were previously expressed in a linear measure. In the first case, the error in matching the two systems does not exceed 2 cm on the Earth`s surface. In the second case, the propagation error of PZ-90 by the GLONASS is at the level of 10 cm, which satisfies the given technical requirements.