A wire covering material composition which is systematically different from a polyolefin resin composition and which possesses favorable flame retardancy, tensile elongation and wear resistance, having 100 parts by weight of a polymer blend containing 40-95 wt % of polybutylene terephthalate, and 1 to 30 parts by weight of a phosphoric ester compound with respect to 100 parts by weight of the polymer blend, wherein 5 to 100 wt % of the total content of the polybutylene terephthalate in the polymer blend is made up of polybutylene terephthalate, whose molecular weight distribution Mw/Mn (where Mw: weight-average molecular weight; Mn: number-average molecular weight) is greater than or equal to 2.5.