In the present work, CuCl nanoparticles were fabricated in deep eutectic solvents (DES) which is a new kind of ionic liquid with special properties. The as-prepared samples were characterized by x-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The effect of polyvinylpyrrolidone (PVP), the molar ratio of ascorbic acid to copper chloride and the mixing method were investigated. The optimized reaction conditions were as follows: reaction time is 1 h, reaction temperature is 25 degrees C in the presence of PVP in deep DES. Under the optimum conditions, CuCl nanoparticles with the average size about 50 nm could be successfully prepared in DES.