The present invention provides an energy conversion composition which has an excellent capability of absorbing and damping energy such as dynamic, thermal, or electric energy. The composition can be made into a very thin and small but excellent damping product. The energy conversion composition is characterized in that its base material contains a moment activator which can increase the amount of dipole moments in the base material. The energy conversion composition can be utilized as a vibration damping, sound absorptive, impact absorptive, vibration-proof, electromagnetic wave absorptive, piezoelectric, and endothermal material as well as a polarity liquid.