High-quality SiGe/Si multiple quantum wells (MQW) (20periods) were epitaxia lly grown on an Si substrate by molecular beam epitaxy (MBE).An Si-based wavegu ide photodetector was fabricated and characterized by SiGe/Si MQW as absorption region.Two metal-semiconductor Schottky junctions on and under the waveguide photodetector were fabricated.The results show the dark current of the photodetector with a mesa size of 7500μm is about 0.1μA at the bias voltage of － 2V.The peak value of the photocurrent response is about 1008nm at the bias of 0V.With the increase of the len gth of the absorption region,the response signal is also increased.The results indicate possibility of an integr ated detector for an all Si-based long wavelength receiver.