In this letter, a reflection-type arrayed waveguide grating (AWG) (de)multiplexer using high-reflection photonic crystal reflector (PCR) in the Indium-phosphide Membrane on Silicon (IMOS) platform is proposed and experimentally demonstrated for the first time. This reflection-type AWG enables a 35% size-reduced footprint compared with the traditional transmission-type AWG having the same spectral parameters. Considering the realized performance of silicon-nanowire R-AWGs, an acceptable performance (680×190μm2 size, 6.7-dB loss, and 10-dB crosstalk) is obtained. By using the ultra-small5.4×0.7μm2 PCR, merely 1.1-dB power loss higher than the corresponding transmission-type AWG is implemented. The PCR is a standard building block with a reflectivity of >90%. Besides, the length reduction of the arrayed waveguide will contribute to minimize the accumulated phase error in fabrication.