Abstract: <SPAN lang=EN-US>Cuprous chloride is an important inorganic fine chemical product,which was produced by nantokite reduction method.The yields of cuprous chloride under different acidities of the reaction system were tested by experiments.Effect of acidity on the yield of cuprous chloride and the principle of impact were studied.Study results indicated that when acidity (pH) of slurry was controlled at 3.5 it would give a highest production rate.Based on the study results a new approach to improve the production rate of cuprous chloride by adjusting acidity of slurry was put forward.</SPAN>