The ceramic microsphere was prepared by the ball milling and sintering using Dolomite and Coal Gangue as raw materials. The effects of ratio of raw materials, sintering temperature on bulk density and apparent density, phase constitution, microstructure of the ceramic microspheres were studied. The results indicated that the ratio of raw materials, sintering temperature has some effects on the bulk density and apparent density, phase constitution, microstructure of the ceramic microspheres. The bulk density and apparent density of the ceramic microspheres increased with sintering temperature rising. With the increasing of the ratio of dolomite, the bulk density of ceramic microspheres improved firstly and then dropped slightly, the apparent density of ceramic microspheres increased constantly. The bulk densities of the prepared ceramic microspheres were in the range of 0.570 g/cm3to 0.754 g/cm3, the apparent densities of the prepared ceramic microspheres were between 2.419 g/cm3and 2.661 g/cm3.