It is considered the problem of two natural satellites around a spheric planet. Only gravitational forces act on the system. The satellites move in a central field disturbed by the mutual atraction between them. The disturbing function is developed in power series of the small parameter (ratio of mass of satellites and planet), of the eccentricities and inclinations (assumed small) of the satellites' orbits. The mean motions are supposed to be commesurable in the ratio 2:1. It is, also, assumed that the critical angles are of inclination type. The critical angles of eccentricity type circulates and may be eliminate as fast variables like the short-periodic terms. The hamiltonian is truncated up to the second order in the inclinations.