The intent of this paper is to study the motion of a kind of hydric nonholonomic systems.The motions of the system can be divided into three stages.The first stage is the continuous motion of a holonomic system.The second stage is an impulse motion.The third stage is the continuous motion of a nonholonomic system.The initial conditions of the last stage are detemined by the final condition of the preceding stage.An example is given to illustrate the application of the result.