Propylene glycol is used as the carrier of medicine and agent of particle medicine, as a solvent of perfume and edible pigments, emollient in food packing, and anti-adhesive, as humidor, emollient and solvent, it also can be used as tobacco flavor, lubricated solvent, and preservative. As the raw material of non-saturated alkyd resin, plasticizer, dehydration, surface active agent, solidification agent, and cohesive agent. It also used in paint industry, pesticide industry and dope industry etc.