Disclosed are a steel composition and a spring steel comprising the same. The steel composition comprises: an amount of about 0.51 to 0.57% by weight of carbon (C), an amount of about 1.35 to 1.45% by weight of silicon (Si), an amount of about 0.95 to 1.05% by weight of manganese (Mn), an amount of about 0.60 to 0.80% by weight of chromium (Cr), an amount of about 0.25 to 0.35% by weight of copper (Cu), an amount of about 0.05 to 0.15% by weight of vanadium (V), an amount of about 0.25 to 0.35% by weight of nickel (Ni), an amount of about 0.003 to 0.015% by weight of phosphorus (P), an amount of about 0.003 to 0.010% by weight of sulfur (S), and iron (Fe) constituting the remaining balance of the steel composition, all the % by weights are based on the total weight of the steel composition.