Recovery or Extraction of metals have been conducted by hydrometallugical or pyrometallurgical methods. In recent years, reserach on the hydrometallurgical process and investment reduction. In this study, the effect of physical pre-treatment on metal liberation was studied as the preliminary step for the hydrometallurgy recovery of valuable metals from PCBs. The physical pre-treatment comprises crush, magnetic sepatation, air separation and size separation steps. Two different pre-treatment processes were selected comprising the pre-treatment steps. The degree of liberation of both processes was confirmed by direct measurement as well as indirect measurement through leaching experiment in nitric acid. The Cu leaching rates of both processes were 33% and 100% at the same experimental condition i.e. 2 mole nitric acid, reaction temperature of 90℃, pulp density 100g/L, 300 rpm, and reaction time of 1 hr.