The influence of casting cooling rate during the preparation of ingots on the grain size distribution and the magnetizing ability of $ extrm{Nd}_{16} extrm{Fe}_{72} extrm{V}_{4} extrm{B}_{8}$ sintered magnets were investigated. Sintered magnets prepared from copper mold which allow a higher cooling rate, show a smaller grain size distribution and god magnetizing ability. The effects of adding bride forming elements, such as Cr, Mn, Nb, and W on the magnetic properties of Nd-Fe-B sintered magnets were also investigated. Both Cr and W addition increase coercivity and the resultant $ extrm{Nd}_{16} extrm{Fe}_{72} extrm{Cr}_{4} extrm{B}_{9}$ alloy exhibits a similar magnetizing ability in comparison with $ extrm{Nd}_{16} extrm{Fe}_{72} extrm{V}_{4} extrm{B}_{8}$ alloy.