The properties of extrasolar planets perturbations under the influence of nearby stars are investigated. If the mass of the star is sufficiently small, or the velocity of the star is sufficiently large, or the distance between stars is sufficiently large, the planet's motion is integrable. Conditions of extrasolar planet's motion without escape and exchange are derived numerically. Values of orbit's perturbations depending on the nearby star are obtained.
This study was supported by the Russian Foundation for Basic Research (grant 05-02-17408) and by the Scientific Program "Russian Universities" (project ur.02.01.301).