Abstract: The development of a new kind of interlayer on the surfaces of two double base solid propellents through the application of the plasma polymerization technique. The interlayer is a smooth and ultrathin film . It sticks last to the double base solid propellents and considerably enhances the adhesive strength between the ethyl cellulose inhibitor coating and the double base solid propellent . This discovery solves the long existing problem of poor adhesion, thus initiating a new interlayer technology in propellents .