Copper alloys have been used for plain bearing material in many kinds of engineering machines. In this study typical copper alloys are selected from the view point of strength and thermal conductivity that is proportional to electric conductivity. The aim of this study is to investigate that the thermal conductivity is very important character to keep mild friction with appropriate condition of block-on-ring tests. The results show that the patterns of friction coefficient of time are classified into four types. Type I is stable in low friction. Type II is slightly up in the end part. Type III is less stable and up to 0.4 level of friction coefficient (μ). Type IV is rough waving in more over 0.4 level of friction coefficient (μ). The materials of Type I are chromium copper alloy and Corson copper alloy. The Type II is beryllium copper alloy. These Type I & II alloys have the same properties of high thermal conductivity and characteristic microstructure of dispersed hard particles in copper matrix. High thermal conductivity reveals good tribological performance, i. e., low friction and wear. Moreover after tribological test, the surface of these alloys changes and transformes to rich oxide surface with condensed hard particles. It’s action is simple application of friction steps to escape the severe wear. Especially the copper alloy with ferrous particles dispersed in matrix makes severe mode of friction by the same element of friction.