Abstract: The composite effect of the hybrid magnets bonded by nanocrystalline Nd2Fe14B/Fe3B with ferrite powders was studied, as well as the influence of its variations in magnetic properties, temperature coefficient βjHc of intrinsic coercive force jHc and thermal stability and the composite effect itself on its density and compressive strength. The results show that the composite effect makes its temperature coefficient βjHc and irreversible loss hirr decrease with the thermal stability improved. The effect of the content of ferrite on its magnetic properties at 100°C shows that the remanence Br and maximum magnetic energy product(BH)m decrease but the intrinsic coercive force jHc increases obviously. The composite effect affects its magnetic properties and density obviously but affects compressive strength slightly.