Based on chaos theory and via experiments, the evaluation for the nonlinear characteristics of the time series of the rolling element bearing friction torque was studied in order to lay a foundation of accurately calculating the dynamic performance of the rolling element bearing friction torque. The standard deviation of the relation dimension was used to depict the uncertainty of the friction torque and the mean of the relation dimension was used to describe the evolutive history of the nonlinear characteristics of the friction torque. The investigation indicates that the rolling element bearing belongs to the certain nonlinear dynamics system, but its friction torque presents the obvious uncertainty. As the rotational speed is raised both the standard deviation and the mean of the relation dimension of the rolling element bearing friction torque take on the nonlinearly increasing trend.