The ceramic ball bearing has been used to exact machine for its good properties such as heat-resistant, corrosion-resisting, and wear-resisting. The old grinding methods of ball bearing spend much time and power. Although the magnetic fluid grinding method economizes time, but cost much money. This study research the effects of spindle speed, grit size, load, and the material of float-ring and fixed-ring on the grinding characteristics by using a new ultra-precision ball grinding machine which developed by our lab. Search the optimum operating conditions of this machine for the requirement of industrial circles. Experimental results show that the converge rate of the saturated value for the sphericity, surface roughness (Ra), and the removal rate are increased with increasing spindle speed, grit size, or load. The sphericity and surface roughness (Ra) are increased when spindle speed, grit size, or load is increased. The sphericity and surface roughness (Ra) are increased with increasing removal rate in using the same grit size and load. Under a certain operating parameter of grinding process, the mean diameter and removal rate are decreased with increasing grinding time. The sphericity and surface roughness (Ra) are better when using the plastic than the float-ring and fixed ring of aluminum, but its removal rate is lower than aluminum¡¦s. First, let the average sphericity achieve saturated value by using diamond grind disk to grinding the Al2O3 ceramic ball. Then, the optimum sphericity can achieve 0.7£gm and the surface roughness (Ra) can achieve 0.1£gm by using the B4C grits of 0.5£gm to grinding.