This paper analyzes the motion of a horseback riding robot which has two actuators and three joints. It is impossible to control the saddle to get to any position and orientation using the two motors because the robot has less degrees of freedom than the number of joints. Therefore it is required to know the possible location and orientation along with the velocity characteristics of each pose prior to motion planning. For this purpose, this paper analyzes the characteristics of the robot motion. The authors derive the forward and inverse kinematics of the robot motion and developed the trajectory editor for motion planning. Also, Jacobian of the robot is analyzed. It reveals that one of the actuator has little influence to the speed of the saddle motion while the other affects the speed of the saddle motion dominantly. The approach of the paper can be applied for the analysis of characteristics of a robot which has less number of actuators than that of joints.