Abstract: A rolling velocity control method for a spherical mobile robot is implemented. Nonlinear relationships between the control-input and state-output of the spherical mobile robot are hard to be described by exact mathematical model, with the radial basis function neural network, nonlinear mapping from the inputs to outputs of the robot are established by online training. Thereafter the velocity controller of the robot is designed by feedback linearization method, and it is composed of a feedback linearization controller and a compensation controller for reducing approximation errors of neural network. The implementation of the controller is given. Experiments show that the velocity control for the spherical mobile robot can be achieved stably by this method.