By means of X-ray diffraction analysis, it is shown that for X =< 2.0 all of the SmFe 1 0 . 7 - X Mo 1 . 3 Ga X compounds crystallize with ThMn 1 2 -structure. The lattice parameters increase linearly with Ga concentration. Ga occupies 8j and 8f sites, as shown by powder X-ray diffraction pattern refinement. The composition dependence of Curie temperatures shows that the T C decreases monotonically with Ga content from 495 K for X = 0 to 420 K for X = 2.0. The saturation magnetization M s at 4.2 and 300 K also decreases linearly with increasing of Ga content from X = 0 to X = 2.0. The anisotropy B a is smaller at X = 0.5 than for X = 0, and the magnetocrystalline anisotropy of SmFe 1 0 . 7 - X Mo 1 . 3 Ga X compounds changes from uniaxial to conical for X >= 1.0 in SmFe 1 0 . 7 - X Mo 1 . 3 Ga X compounds.