The analysis method of contact stresses between balls and inner/outer ring raceway of large-sized four-contact-point ball bearing with negative axial play is present. The contact stresses and contact areas between balls and inner/outer ring raceway of a slewing ring bearing are computed at different negative axial plays without applied load. The results show that a ball contacts with inner/outer ring raceway at four points whose contact areas and contact stress distribution are approximately same. The contact stresses between balls and inner ring raceway are slightly higher than those at outer ring raceway. Contact stress and contact area increase with absolute value of negative axial play increasing. Startup friction torque can be improved by increasing the absolute value of negative axial play.