Abstract: Disclosed is a high-strength spring steel containing C, Si, Mn, Ni, Cr, Mo, V and the like within the specified range, wherein the above components satisfy the following equation:550-333[C]-34[Mn]-20[Cr]-17[Ni]-11[Mo].gtoreq. 300where [C, Mn, Cr, Ni, or Mo] represents wt % of each component, and the average diameter of the non-metallic inclusions of oxides is specified. By use of the above steel, there can be obtained a high-strength spring steel having a tensile strength of 200 kgf/mm.sup.2 or more and being excellent in the fatigue characteristic and the sag resistance. Further, in the above steel, each content of C, Si, Ni, and Cr may be added to satisfies the following equation:50[Si]+25[Ni]+40[Cr]-100[C].gtoreq. 230where [Si, Ni, Cr or C] represents wt % of each component. Thus the corrosion fatigue characteristic is also improved.