Si distributed Bragg reflector with crystal Si thin film on the reflector was fabricated by electron beam evaporation and bonding techniques.Narrow band Si resonant-cavity-enhanced(RCE) metal-semiconductor-metal(MSM) photodetectors were fabricated by standard photolithography with responsivity peaks at 836 nm,900 nm,965 nm and 1 030 nm respectively.The full-width-at-half-maximum was about 18 nm at 900 nm.The wavelength selectivity of the device could eliminate crosstalk between channels,and the integrated array could be easily realized.