The (Nd,Dy)-(Fe,Al)-B alloys with different rare earth (RE) contents were prepared using melt-spun and strip cast techniques, and the dependence of their microstructures and magnetic properties on RE contents were investigate. It is found that an appropriate RE in magnets is beneficial to the formation of (Nd,Dy)2Fe14B single phase and uniform distribution of the Nd-rich phase on grain boundaries. When the rare earth content of casting strip treated as main phase is close to the stoichiometric concentration, the coercivity and energy product of magnet are enhanced significantly. Moreover, heat treatment of casting strips can improve effectively the magnetic performance of final sintered magnets.