Sr-La-Co M-type ferrite powders were prepared by the mechanical compounding method using the planetary ball-mill and subsequent heat treatment. This experiment was carried out to investigate magnetic properties of bonded magnet using M-type ferrite powders prepared by Mechanical compounding method. The properties and making condition of typical sample are as follows; Chemical composition: SrO⋅6.3Fe₂O₃ in addition with 2.0 wt% La₂O₃ and 0.3 wt% Co₃O₄; planetary ball-mill condition: 300 rpm × 1 h; heat treatment condition: 1200°C×4h in air; centrifugal mill time: 1 h; binder: Nylon6 (ejection molding); magnetic properties are J_r= 0.252T; H_cJ=307kA/m; (BH)_max=12.3 kJ/m³ and density: 3.57 Mg/m³.