[en] Results of investigation into magnetic anisotropy of La_1-x(Sr, Pb)_xMnO_3+γ composition crystals with x=0.1 and 0.3 are given. All measurements are conducted within 77-300 K temperature range using polycrystalline specimens of cubic perovskite structure which rhombohedral distortion and a=7.770 A lattice double constant. The obtained results show, that magnetic anisotropy is not cubic one. Growth of annealing temperature increases magnetic anisotropy constant. Crystals with strontium (x=0.3) increased content have higher constant of magnetic anisotropy that of crystals with x=0.1