PURPOSE: To obtain a composite wire having excellent fatigue limits by applying working strain to a coating metal which coats the outside circumference of a core wire by cold rolling at specific working rates.

CONSTITUTION: A composite roughly drawn wire wherein a metal for coating is coated on the outside circumference of a core wire is subjected to ≥60% reduction working with caliber rolls of 2-way or 3-way rolls. Here, if the reduction rate of area is <60%, the hardening by the working is insufficient and strength cannot be improved. For example, if this method is adapted to an Al-coated steel wire wherein Al having 0.75mm thickness is extrusion-coated on the outside circumference of a 3.5mm steel wire, the fatigue strength thereof is 5.1W5.9kg/ mm2 and the steel wire which is not subjected to reduction working or is subjected to reduction working at <60% reduction of area, has 3.2W4.5kg/mm2 fatigue strength.