The hydrogenation of HgCdTe photoconductive(PC) detectors passivated with anodic oxide(AO) and ZnS by Hplasma has been investigated. After hydrogenation the detectors passivated with AO showed a degradation of performance with lower signal and higher noise. From the surface topography of the sample, the original blue anodic oxide almost disappeard, and from rcsponsivity spectrum, the responsivity in the shorter wavelength direction was depressed. It was considered that H ions directly bombarded the HgCdTe surface after the AO was consumed, which induced an increase in surface recombination velocity of the minority carriers. However, for detectors passivated with ZnS, the performance was improved after hydrogenation,showing higher signal and lower noise, and from the FTIR spectrum the responsivity in the shorter wavelength direction was lifted up. From surface topography a slight change was found for the color of ZnS, and a step of about 70nm appeared by XP2 step profiling. With SIMS analysis H+ was found to penetrate through ZnS and reach the interface between ZnS and HgCdTe, and the improvement of performance after hydrogenation was thought due to the passivation of interface states by H ions.