There is provided a linear object comprising magnesium-alloy having not only excellent heat resistance but also excellent plastic formability. The linear object comprising magnesium-alloy contains, on a mass percent basis, 0.1% to 6% Y, one or more elements selected from the group consisting of 0.1% to 6% Al, 0.01% to 2% Zn, 0.01% to 2% Mn, 0.1% to 6% Sn, 0.01% to 2% Ca, 0.01% to 2% Si, 0.01% to 2% Zr, and 0.01% to 2% Nd, and the balance being Mg and incidental impurities, in which the linear object comprising magnesium-alloy has a creep strain of 1.0% or less, the creep strain being determined by a creep test at a temperature of 150°C and a stress of 75 MPa for 100 hours.