Abstract: Using Mg powder and B powder as the main raw materials,MgB₂ superconductors were fabricated under different sintering methods.X-ray diffractometer,scanning electron microscopy,the Archimedes method and the standard four-probe resistivity detection method,et al.were used to investigate the phase composition,the microstructure,the density,the critical current density and so on of MgB₂ samples.It is found that the density of MgB₂ bulk decreases with the Mg particle size increasing.The rapidly sintered MgB₂ bulks possess lower density and more non-superconducting phases,such as Mg and MgB_x（x = 4,6 or 12） than the conventionally sintered ones.The rapidly sintered MgB₂ wires exhibit lower critical current density than those conventionally sintered wires.It is revealed that the rapidly sintering method is unfit for the fabrication of high performance MgB₂ superconductors.