NOVELTY - A lubricant composition comprises mineral oil and/or hydrocarbon type synthetic oil as base oils with dynamic viscosity of 2-5 mm2/s at 100 degrees C, viscosity index of greater than or equal to 90, sulfur content of less than or equal to 0.01 mass%, aromatic content (%Ca) of less than or equal to 5, phosphorus content (%Cp) of greater than or equal to 80, and gas chromadistillation fraction of less than or equal to 10 mass% at 300 degrees C. Amount of zinc dialkyldithiophosphate is 0.05-0.09 mass% in which alkyl group is 3-8 carbon containing alkyl, and of molybdenum-sulfide dialkyl dithiocarbamate is 0.02-0.15 mass%.    USE - A lubricant composition for internal combustion.    ADVANTAGE - Lubricant composition is excellent in low-viscosity and low friction performance with high energy saving property.    DETAILED DESCRIPTION - A lubricant composition comprises mineral oil and/or hydrocarbon type synthetic oil as base oils with dynamic viscosity of 2-5 mm2/s at 100 degrees C, viscosity index of greater than or equal to 90, sulfur content of less than or equal to 0.01 mass%, aromatic content (%Ca) of less than or equal to 5, phosphorus content (%Cp) of greater than or equal to 80, and gas chromadistillation fraction of less than or equal to 10 mass% at 300 degrees C. Amount of zinc dialkyldithiophosphate is 0.05-0.09 mass% in which alkyl group is 3-8 carbon containing alkyl. Phosphorus content derived from zinc dialkyldithiophosphate of 1st class alkyl group is greater than phosphorus content derived from zinc dialkyldithiophosphate of 2nd class alkyl group. Amount of molybdenum-sulfide dialkyl dithiocarbamate is 0.02-0.15 mass%. Composition does not contain sulfur compound consisting of dialkyl dithiocarbamic acid metal salt, organic disulfide type sulfur compound, thiadiazole compound, sulfurized olefin, sulfuration fish oil, and sulfuration whale oil. Composition has dynamic viscosity of 4.5-8.2 mm2/s at 100 degrees C and high temperature high shear viscosity of 1.5-2.2 mPa.s at 150 degrees C.