Spring vibration isolators and rubber damping vibration isolators are often used in active isolation engineering of water source heat pump units. The method is inefficient in shock and low frequency vibration isolation. Because the stiffness of equipments reduces with the isolation system the vibration severity itself becomes too big for working safely. Particle damping materials can absorb vibration energy to reduce vibration. The paper testifies that successful application of particle damping materials in vibration reduction of water source heat pump units is a practical simple way with low cost.