By rneans of correlation analysis, resonance interaction between Uranian rings and new satellites predicted earlier, is proved, Instability of circular rings relative to the disturbance with the azimuthal number m =1 is shown; it may be the cause of the ring’s eccentricity. This justifies the authors' hypothesis that the formation of eccentric rings of the protodisk around Uranus ia due to unknown Uranian satellites, There is no longer necessity for the hypothesis of the existence of "shepherd"-satellites in Uranian rings which have not been discovered by Voyager-2. A new - accretion instability of the protodisk is described which may háve served as a generator of the birth of a large-scale structure of Saturn’s rings, The discovery of the instability makes it possible to understand the origin of the hierarchic structure of Saturn’s rings, since the mechanisms of formation of narrow ringlets were investigated earlier.