With a view to observe the complexity nonlinear phenomena of a rotor-bearing system with rub-impact
the multi-initial condition bifurcation analysis method was used in the study.And more abundant nonlinear phenomena were found than that of the single initial point integration method by the numerical simulation of the rub-impact rotor-bearing system in definite parameters.It was shown that multiple attractors coexisted in a range of parameters.Meanwhile the solution variation was also studied
which effectively explained the complex nonlinear phenomena of the rotor-bearing systems.