Abstract: The effect of wire finished rolling temperature and cooling rate at I 〜HI section of Stelmor cooling line on thickness of oxide scale, ingredient and structure and flaking properties of coil of steel 72A (/% : 0. 70 ~0. 75C, 0. 15 〜 0. 35Si, 0. 35 ~0, 60Mn, ≤ 0. 025P, ≤ 0. 025S) has been studied by SEM and bending test. Results show that the descaling performance of oxide scale is mainly associated with thickness of scale, and the scale with thickness 10 ~ 12 μm has better mechanical-descaling performance ； the thickness of FeO layer is positively correlated with the descaling performance of scale, and the scale with thickness more than 9μm has better descaling performance, while the Fe₃O₄ layer is negatively correlated with the descaling performance of scale； with increasing cooling rate the thickness ratio of FeO layer increases, with outlet wire temperature up to 910℃  , increasing cooling rate of coil at Stelmor cooling line i. e. 6 ~ 7. 5 ℃ /s at I section and 12 ~ 20 °C/s at Ⅱ section the mechanical-descaling performance of high carbon steel coil is effectively improved.