Radial-axial ring rolling is a process widely used to produce large precise seamless rings. The regulation of rotation speeds between main roll and axial rolls and tangential slip between main roll and ring influence greatly the rolling process. In this paper, an equation governing regulation of rotation speeds is derived. Influences to rotation speeds from conic angle and contact position are analyzed. Equation of relative tangential slip speeds in both inner and outer diameters are established, which are employed to creat a condition of non tangential slip in radial-axial ring rolling process.