The a-Si:H/a-SiNx:H multilayer films were prepared by a glow discharge CVD method. Hydrogen radical produced by H-2 plasma was alternately exposed to both a-Si:H and a-SiNx:H sublayer surfaces while suspending the deposition of each sublayer. The microstructure of the a-Si:H/a-SiNx:H multilayer films with hydrogen radical exposure and without hydrogen radical exposure was studied by means of small angle XRD, IR and Raman scattering measurements. The results indicate that the induced hydrogen radical may break the distorted or unstable Si-Si bonds on the a-Si:H and a-SiNx:H sublayer surfaces, and that the excessive H atoms at the interfaces of the a-Si:H/a-SiNx:H multilayer films may compensate for the surface silicon dangling bond by forming the Si-H bond. It was found that the microstructure of the multilayer films depends strongly on the hydrogen radical expo sure time. The value of the silicon bond angle deviation in the a-Si:H(50A)/a-SiNx: H(50A) multilayer film changes from 10 to 7.9 to 12.1 degrees with increasing hydrogen radical exposure time from 0 to 10 to 60 s, correspondingly Given the exposure time of 10 a, the multilayer film is of the abruptest interface and smallest deviation of interfacial silicon bond angle.