A vane pump comprising: a rotor having a plurality of slots formed on an outer circumferential surface thereof; a vane slidably inserted into each of the slots; and a cam ring having the rotor therein and having a inner circumferential surface in contact with an end portion of the vane, wherein the rotor is formed of nodular graphite cast iron, the vane is formed of high speed tool steel, and the cam ring is formed of alloy cast iron, and wherein at least one of the nodular graphite cast iron, the high speed tool steel, or the alloy cast iron contains following materials by weight ratio: the nodular graphite cast iron having an austenite structure including 3.5% to 3.9% of carbon, 2.2% to 3.0% of silicon (Si), 0.1 % to 0.5% of manganese (Mn), 0.02% or more of sulfur, 0.04% or more of phosphor, 0.1% to 0.5% of copper (Cu), 0.1% to 0.3% of molybdenum (Mo), 0.02% to 0.05% of magnesium, and 0.01% to 0.04% of rhenium (Re) by weight ratio, and the remainder being iron (Fe) and unavoidable impurities; the alloy cast iron including 3.0% to 3.3% of carbon, 2.0% to 2.5% of silicon (Si), 0.5% to 1.0% of manganese (Mn), 0.05% to 1.0% of chromium (Cr), 0.2% to 0.5% of copper (Cu), 0.1 % to 0.3% of phosphor, 0.02% to 0.06% of boron, 0.06% to 0.1 % of sulfur, and 0.4% or more of titanium (Ti), by weight ratio; or the high speed tool steel including 0.8% to 0.9% of carbon, 0.2% to 0.45% of silicon (Si), 0.15% to 0.4% of manganese (Mn), 0.03% or more of sulfur, 0.03% or more of phosphor, 3.0% to 4.4% of chromium (Cr), 4.5% to 5.5% of molybdenum (Mo), 1.75% to 2.2% of vanadium, and 5.5% to 6.75% of tungsten by weight ratio, and the remainder being iron (Fe) and unavoidable impurities. a rotor having a plurality of slots formed on an outer circumferential surface thereof; a vane slidably inserted into each of the slots; and a cam ring having the rotor therein and having a inner circumferential surface in contact with an end portion of the vane, wherein the rotor is formed of nodular graphite cast iron, the vane is formed of high speed tool steel, and the cam ring is formed of alloy cast iron, and wherein at least one of the nodular graphite cast iron, the high speed tool steel, or the alloy cast iron contains following materials by weight ratio: the nodular graphite cast iron having an austenite structure including 3.5% to 3.9% of carbon, 2.2% to 3.0% of silicon (Si), 0.1 % to 0.5% of manganese (Mn), 0.02% or more of sulfur, 0.04% or more of phosphor, 0.1% to 0.5% of copper (Cu), 0.1% to 0.3% of molybdenum (Mo), 0.02% to 0.05% of magnesium, and 0.01% to 0.04% of rhenium (Re) by weight ratio, and the remainder being iron (Fe) and unavoidable impurities; the alloy cast iron including 3.0% to 3.3% of carbon, 2.0% to 2.5% of silicon (Si), 0.5% to 1.0% of manganese (Mn), 0.05% to 1.0% of chromium (Cr), 0.2% to 0.5% of copper (Cu), 0.1 % to 0.3% of phosphor, 0.02% to 0.06% of boron, 0.06% to 0.1 % of sulfur, and 0.4% or more of titanium (Ti), by weight ratio; or the high speed tool steel including 0.8% to 0.9% of carbon, 0.2% to 0.45% of silicon (Si), 0.15% to 0.4% of manganese (Mn), 0.03% or more of sulfur, 0.03% or more of phosphor, 3.0% to 4.4% of chromium (Cr), 4.5% to 5.5% of molybdenum (Mo), 1.75% to 2.2% of vanadium, and 5.5% to 6.75% of tungsten by weight ratio, and the remainder being iron (Fe) and unavoidable impurities. the nodular graphite cast iron having an austenite structure including 3.5% to 3.9% of carbon, 2.2% to 3.0% of silicon (Si), 0.1 % to 0.5% of manganese (Mn), 0.02% or more of sulfur, 0.04% or more of phosphor, 0.1% to 0.5% of copper (Cu), 0.1% to 0.3% of molybdenum (Mo), 0.02% to 0.05% of magnesium, and 0.01% to 0.04% of rhenium (Re) by weight ratio, and the remainder being iron (Fe) and unavoidable impurities; the alloy cast iron including 3.0% to 3.3% of carbon, 2.0% to 2.5% of silicon (Si), 0.5% to 1.0% of manganese (Mn), 0.05% to 1.0% of chromium (Cr), 0.2% to 0.5% of copper (Cu), 0.1 % to 0.3% of phosphor, 0.02% to 0.06% of boron, 0.06% to 0.1 % of sulfur, and 0.4% or more of titanium (Ti), by weight ratio; or the high speed tool steel including 0.8% to 0.9% of carbon, 0.2% to 0.45% of silicon (Si), 0.15% to 0.4% of manganese (Mn), 0.03% or more of sulfur, 0.03% or more of phosphor, 3.0% to 4.4% of chromium (Cr), 4.5% to 5.5% of molybdenum (Mo), 1.75% to 2.2% of vanadium, and 5.5% to 6.75% of tungsten by weight ratio, and the remainder being iron (Fe) and unavoidable impurities.