The effect of Zr, Mo or Y doping on mechanical and electrical properties of Pt-Ir binary alloys was investigated. The alloys were prepared in a vacuum high frequency melting furnace. X-ray diffraction and metallographic microscopy were employed to detect the microstructures. Electric bridge and eddy current conductive instrument were employed to test the electrical resistivity and the mechanical properties of alloys were tested by AG-X100KN type tensile testing machine. The results show that adding rare metal elements into Pt-Ir system could refine structure effectively, increase the melting point, density, mechanical properties and electrical resistivity of the alloys, but decrease the processing property.