A copper alloy wire rod having an alloy composition containing 0.5 to 6.0% by mass of Ag, 0 to 1.0% by mass of Mg, 0 to 1.0% by mass of Cr, and 0 to 1.0% by mass of Zr, with the balance being Cu and inevitable impurities, wherein an average closest particle distance of second phase particles having a particle size of 200 nm or less is 580 nm or less in a cross section perpendicular to a longitudinal direction of the wire rod.