the resonance a special parameter called “resonant argument” is introduced. It is linear combination of the mean longitudes and the longitudes of periapsis. In planar problem it is defined by the following formula: σ = mP1λP1 + mP2λP2 + mλ + pP1 P1 + pP2 P2 + p , where λP1, λP2, λ, P1, P2, — mean longitudes and longitudes of periapsis of two planets and an asteroid respectively and mP1, mP2, m, pP1, pP2, p — are integers followed by D’Alembert rule (see Morbidelli, 2002): mP1 + mP1 + m + pP1 + pP2 + p = 0. E.A Smirnov. Three-body resonances. Asteroids in three-body mean motion resonances with planets