cyclo-pentane can be used as a new foaming agent for rigid polyurethane foam and can be substituted for CFCS which distroies the atmospheric ozone layer. Now it is widely used in producing non-CFCS refrigerator, freezer and cold storage and tubing insulating materials. With the coming of the deadline to use ODS by Montreal protocol; CFCS and HCFCS will prohibited soon, and cyclo-pentane will be play a key role in the polyurethane foam applications.