One of the factors which has the most important effects upon the strength of stayed masts is the tensile characteristics of wire ropes used as stays. The tensile test of them was tried by the author, and the results of the test is summarized as follows. The elastic coefficient of wire ropes can be described by the experimental formula, E_w=100(21.3P/D+0.6W_p/A-81) ……On increasing load E_w=100(27P/D-43) ……On decreasing load where: E_w kg/mm²……Elastic Coefficient of a wire rope P mm……Pitch of a wire rope D mm……Diameter of a wire rope A mm²……Metalic area of the section of a wire rope W_p kg……The maximum tensile force that the wire rope has ever been loaded