Abstract: The principles of plasma ion-assisted deposition(IAD)and a new high vacuum plasma sotirce are introduced.With a hollow cold cathode discharge,the plasma sotirce can be operated in ambient pressure from 1×10-3pa to 1×10-1pa,the reactive gas and the nonreactive gas can be used as working gas.The energy of Ar- in argon plasma,h1eatstired with a Longmuir probe,is 50～80eV,depending on pressure and discharge current density.It has been experimentally confirmed that both the optical properties and mechanical properties of single-layer films of ZnS and SiO2 prepared in argon plasma and oxygen plasma have been improved considerably as compared to those films obtained with traditional vapor deposition.