A simplified dynamic model of single wheelset under traction was established to study its lateral stability. The hunting stability was analyzed on different adhesion conditions between wheel and rail. The results show that a single wheelset has a better lateral stability under traction than under idle running, and that when the average creep is 0.8% the nonlinear critical speed of an elastically positioned single wheelset under traction is 1.1 times of that under idle running. Wheel/rail adhesion saturation results in a decrease in wheelset yaw torque, and a decrease in driving torque causes an increase in lateral creep force, both of which are in favor of wheelset stability.