Abstract: The bonded NdFeB magnet was prepared with NdFeB magnetic powders and polyimide. The effect s ofparticle size of magnetic powders , coupling agent content , adhesive content , molding pressure and adhesive propertyon the magnetic and mechanical properties of bonded magnet s were studied. The results indicate that the bondedNdFeB magnets with good properties can be obtained by a proper ratio of big particles to small particles , appropriateamount of coupling agent and adhesive , proper pressure and polyimide. The ratio of the coarse particles to the fineones was 33 to 67. The content s of coupling agent and adhesive were 0. 9 % and 3. 2 % , respectively. The properpressure was 600 MPa.