Ni-doped Na0.5Bi0.5TiO3 crystals were synthesized and studied by X-ray diffraction (XRD), X-ray spectroscopy (EDS), and magnetic property measurement system (MPMS). Room-temperature ferromagnetism has been observed in Ni-doped Na0.5Bi0.5TiO3 crystals. It was found that the magnetism of NBT crystals can be controlled by Ni doping concentration. The magnetism of the Ni-doped Na0.5Bi0.5TiO3 crystals develops from diamagnetism to ferromagnetism and paramagnetism on increasing Ni doping concentration from 0 to 1.25mol %. The results presented in this study may provide an approach to widely exploring more multiferroic materials.