Effects of copper addition on physical and mechanical properties of sintered manganese steel were studied. The results obtained were as follows :(1) The addition of copper to iron and manganese by mixing process has not a good effect of improving the sintering between iron and manganese, as liquid phase of copper and iron-copper alloy formation prevent the sintering between iron and manganese.(2) The addition of copper-manganese alloyed powder to iron can make alloying of copper and manganese to iron, and can increase the tensile strength as compared with copper addition only.(3) Copper infiltrated sintered manganese steel has good mechanical properties, for example, tensile strength of 69.3Kg/mm2, and elongation of 5.0%, In order to obtain sintered Fe-Mn-Cu compacts having good mechanical properties, the method of copper infiltration to sintered manganese steel is most recommended. (Received March 17, 1966)