The invention provides a mobile carriage which is adapted to shift the center of gravity efficiently by utilizing the weight of wheel rotating means, power source means and control means to thereby increase the weight of a weight portion and reduce the increase in the weight of the entire carriage, the carriage comprising a base frame, a front wheel and a rear wheel which are disposed under the base frame, wheel rotating means coupled to the front wheel and the rear wheel for rotatingly driving the wheels, power source means for the wheel rotating means, center-of-gravity shifting means having a weight portion disposed above the base frame and a mechanism for moving the weight portion relative to the base frame to shift the position of the center of gravity of the base frame by moving the weight portion by the moving mechanism, and control means for controlling the wheel rotating means and the moving mechanism, the carriage being characterized in that at least one of the wheel rotating means, the power source means and the control means is utilized as the weight portion of the center-of-gravity shifting means.