Using induction plasma, spheroidization, densification, refinement and purity of molybdenum powder were realized, Dense spherical powders with high purity were prepared. The effects of the plasma power and particle size of raw molybdenum powder on spheroidization efficiency of products were studied. The phase composition，morphologies and particle size distributions of the powder before and after spheroidization were characterized by x-ray diffraction(XRD),scanning electron microscopy(SEM) and laser micron sizer(LMS).The result show that the spherical molybdenum powder can be obtained from irregular powder after induction plasma spheroidization. The powder presents smooth surface and good disparity, and the spheroidization efficiency is almost 100%.After plasma treatment, the particle size become finer and its distribution is more concentrated. Under otherwise identical conditions, ,spheroidization efficiency increases firstly and then decreases with the increasing of plasma power. When the plasma power is 25kW,the effects of spheroidization is best. Smaller the particle size, higher the spheroidization efficiency is. With the increasing of spheriodization efficiency, the powder flow ability and apparent density have been significantly improved. The molybdenum powder flow ability is improved from 40s／50g to 11s／50g, and the apparent density from 2.3g／cm3 to 6.1g／cm3.