Kinetics behaviors of partial anodic dissolutlon reactions of α-brass （Cu30Zn） were investigated in 0.5N NaCl—0.01N HCl deaerated solution with rotating ring-disc electrode. The partial anodic current densities of zinc and copper(i,zn, and i,cu,) of brass were measured respectively. For the partial reactions and the total reaction of Cu30Zn, two distinct linear regions in the φ-lg i relations were all found with slopes corresponding respectively to 60 and 130mV. The characteristic of the partial polarization curve of copper shows that the reaction rate is mass-diffusion-controlled for i,Cu,<,lmA/cm,2, and activation-controlled for i,Cu,>,lmA/cm,2,. In case of uniform-dissolution of an alloy in a solution containing no M,n+, a expression for partial anodic reaction polarization curve of constituent M of an alloy was derived: where According to the expression the kinetics parameters of the partial anodic reaction of copper for Cu3OZn were calculated as following: β=0.45, i,Cu,0,*,=2.7×10,-3,A/cm, K=1.1×10,-3,cm/sec.