Abstract: Considering the elasticity of stator and the elastic connection between rotor and stator, a dynamic model of rotor system was developed with the rub-impact fault and gyroscopic effect both coming to pass. Getting the system response through numerical integration, the effects of the mass ratio of stator to rotor and eccentric torgue ratio of the two disks on the system bifurcation and chaos were analyzed. The results showed that the main routes the system enters chaos are from the intermittent chaos and the period 3 then through the period-doubling bifurcation. The elasticity of this system restrains the response to chaos to a certain extent in comparison with the system supported rigidly. A conclusion is therefore drawn that the elasticity of stator will get the domain of chaos response and high-order critical speed decreased and greatly affect the high-order critical speed and resonance amplitude, but it slightly affects the low-order critical speed and resonance amplitude.