Abstract: A series of Cu2O/Ag(x) composite catalysts with different molar ratios were synthesized by a liquid phase reduction method. The properties of Cu2O/Ag(x) samples were characterized by SEM, XRD and DRS (UV-Vis-NIR) analyzing methods. The results indicated that in the presence of nanometre metallic Ag, the light absorption of Cu2O/Ag(x) sample was greatly extended to visible and near infrared wavelength regions. With increasing molar ratio of Ag, the absorption intensities of samples enhanced. This implies that Cu2O/Ag(x) composite catalysts exhibit strong absorption of sunlight. The photocatalytic performances of Cu2O/Ag(x) catalysts in the darkness were evaluated using methyl orange (MO) as a degradation target. The results showed that Cu2O/Ag(0.05) sample exhibited the highest photocatalytic activity, while the degradation rate of MO (30 mg/L) reached 892% in 120 min. Inaddition, the photocatalytic mechanism of the Cu2O/Ag(x) composite catalyst system was proposed.