Abstract: The crystallographic structure and magnetic properties of R(Fe_0.8Mn_0.2)₁₂ (R=Y and Nd) compounds and their nitrides have been investigatad by using X-ray diffraction and magnetic measurements.It is found that both Y(Fe_0.8Mn_0.2)₁₂ and NdR(Fe_0.8Mn_0.2)₁₂ compounds are ferromagnetic and their easy magnetization direction (EMD) are respectively along the C-axis and the easy cone. Upon nitrogenation, the lattice parameters,curie temperatures and the satuation magnetizations are geatly enhanced.Furthermore,the EMD is changed into basal plane for Fe sublattice and turns to along the C-axis for Nd sublattice.