Аннотация:Several examples of observational evidences of variations of geometrical and physical characteristics of the innermost regions of Active Galactic Nuclei on the time-scale of years are given. The 15 year long intensive monitoring of NGC 5548 clearly shows significant variations of broad line region (BLR) size on a time scale 6 to 26 days. An analysis of long-term (1984-2003) UBV variations of NGC 4151 shows that the slow changes in the optical continuum are connected with accretion discs (AD) formation and dissipation: during the 1984-1989 deep minimum the former AD is suggested to totally disappear and a new AD to begin to form since 1988-1989, reaching its maximal brightness in 1996. At the same time the fast variations of the continuum are due to flares in AD. For 3C390.3, there is observational evidence of connection between variations in UV and optical continua and radio-jets inner structure. We may figured out, that during the nucleus maximal brightness periods most of the continuum variable radiation is emitted from the jet (\tilde0.4 pc from the nucleus) and ionizes the surrounding gas, creating a BLR that mainly determines in the broad line emission. During the brightness minima the jet contribution to the ionizing continuum is decreasing and the main broad line emission comes from the ”classical” BLR (AD and the surrounding gas). Such a scenario explains two maxima (\tilde30$^d$ and \tilde100$^d$) found in the cross-correlation function describing the time-lag of broad line variations relatively to continuum on the base of the results of 3C390.3 optical monitoring in1996-2001.