The problem of dependence of polar motion on precession-nutation model is discussed in several papers of M. I. Yurkina. It is actual since improvements in numerical, theoretical models are obtained by means of comparing spherical coordinates of points – their calculated values with the observed ones. The former remain to be dependent on the position of the Earth’s axis in space and on the coordinates of its orbiting center. The purpose to divide these motions by means of solution of 3-body problem was not achieved, hence the idea of taking into account «Euler’s shift» [17, 4, 2, 19] became invalid. In answer to Euler’s question «Qu’est ce que l’axe de la Terre» we show that the observed values which describe the motion of the Earth’s axis in spherical coordinates (i. e. relatively to projections of stars or quasars), are related to uncertain point inside the celestial sphere.