A polarization-selective photodetector with high performance is necessary for polarization sensitive systems. A hybrid integrated photodetector is proposed by integrating a silicon resonant waveguide grating with an InP/InGaAs PIN photodetector. The resonant waveguide grating is designed using rigorous coupled-wave analysis method. Parameters of the hybrid integrated photodetector are optimized by finite difference time domain method. The simulated results indicate that the proposed photodetector exhibits high quantum efficiency, large incident angle tolerance, and polarization selectivity in a broad spectral range, which can be used in polarization sensitive systems.