In this work, the success of doping Na into Cu2O thin films by reactive DC magnetron sputtering method at low temperature is described for the first time. The characteristics of crystal structure, morphology, optical, electrical properties and binding of elements in Cu2O:Na thin films are carefully investigated. The Cu2O:Na thin films have exhibited high electronic conductivity as p-type semiconductor and absorption in visible range. The highest hole concentration on the order of 1018 cm-3 and the lowest resistivity of 6.726 Ω · cm according to 6.56% Na impurities in Cu2O:Na lattice are also detected. The role of Na impurity in Cu2O structure is proposed that based on the changing of structure and alignment of elements.