The contribution to the gravity from the Mars' relief (topography) and the density jump at the Mohorovicic discontinuity (M) in the quadratic approximation have been derived. The problem of determination of possible depths of compensation for relief's harmonics of different degree and order have been solved. It is shown, that almost all compensation of a relief is carried out in a range of depths of 0-1400 km. For various relief's inhomogeneities the compensation is most probable at the depths corresponding to the upper crust ( d = 4.5 ± 3.7 km), to crust-mantle transition layer ( d = 78 ± 24 km); to lithospheric boundary ( d = 200 ± 34 km); to upper-mean mantle transition layer ( d = 400 ± 70 km); to mean-lower mantle transition layer ( d = 1120 ± 180 km). The lateral distribution of compensation masses is determined of this depths, and maps are constructed. The possible stresses in crust and mantle of Mars are evaluated. They reach 10 8 Pa. It is shown that relief' anomalies of volcanic plateau Tharsis and symmetric formation in east hemisphere could arise and be supported dynamically by two plumes of melted mantle substance, enriched by fluids. The plumes have their origins on the boundary depths of lower mantle.