The invention relates to a circumferential movement field, including all circumferential movement devices such as transport vehicle, toy vehicle, space vehicle, blender etc, especially for energy-saving vehicles utilizing force of gravity. The energy-saving vehicle utilizes force of gravity as driving force, the vehicle body connects with the wheel by swing structure method or eccentric swing structure to utilize force of gravity more efficiently. The invention also provides solutions about two-wheel gravitational vehicle and multi-wheel vehicle and train connected by integrated vehicles or two-wheel vehicles.