Abstract: Considering the unbalance oil pressure between the outer squeeze film and inner squeeze film., the whirling motion of the floating-ring was studied. Based on Hirs bulk flow theory , Moody friction factor equation and generalized incompressible Reynolds equation, the transient governing equations for the inner and outer squeeze film and the equation motion of floating-ring were set up. With the help a numerical example, the whirling motion characters of the floating ring were discussed. The results show that the mass center curve of the floating ring is in elliptical from distributed and the prcession radius decreases as the eccentricity of the rotor increases.