(Sm 0.7 Zr 0.3 ) x (Fe 0.9 Co 0.1 ) 100−x (x = 9.1,10.7,10.9,12.6,13.4) alloys almost consist of TbCu 7 type phase were prepared by rapid quenching technique and annealing. A series of TbCu 7 type Sm-Zr-Fe-Co-N magnetically hard powders were prepared through nitrogenization of the alloys. With (Sm 0.7 Zr 0.3 ) content increases, the coercivity increased but magnetization decreases. TbCu 7 -type nitride powder with coercivity of 10.8 kOe can be obtained when x = 13.6. The initial magnetization curves of the powders indicate that the coercivity should be controlled by pinning mechanism. [ABSTRACT FROM AUTHOR]