A lubricating oil composition for an internal combustion engine comprising: a lubricating base oil, having a viscosity index of 100 or higher, an initial boiling point of not higher than 400°C, a 90% distillation temperature of 470°C or higher and a difference between the 90% distillation temperature and the 10% distillation temperature of at least a 70°C, wherein the initial boiling point, the 90% distillation temperature and the 10% distillation temperature are measured according to ASTM D2887-97, an ashless antioxidant containing no sulfur as a constituent element, wherein the content of the ashless antioxidant containing no sulfur as a constituent element is 0.01 to 5 % by mass, based on the total amount of the lubricating oil composition; and at least one selected from among ashless antioxidants containing sulfur as a constituent element, and organic molybdenum compounds, wherein the content of the ashless antioxidant containing sulfur as a constituent element is 0.001 to 0.2 % by mass in terms of the sulfur element, based on the total amount of the lubricating oil composition, and the content of the organic molybdenum compound is 0.001 to 0.2 % by mass in terms of the molybdenum element, based on the total amount of the lubricating oil composition; and wherein the lubricating base oil comprises a first lubricating base oil component having a urea adduct value of not greater than 4 % by mass, a viscosity index of 100 or higher and a kinematic viscosity at 100°C of at least 3.5 mm 2 /s and less than 4.5 mm 2 /s, and a second lubricating base oil component having a urea adduct value of not greater than 4 % by mass, a viscosity index of 120 or higher and a kinematic viscosity at 100°C of 4.5-20 mm 2 /s, wherein said first lubricating base oil component and said second lubricating base oil component are obtained by hydrocracking/hydroisomerization of a feed stock oil containing normal paraffins comprising: a first step in which a normal paraffin-containing feed stock oil is subjected to hydrotreatment using a hydrocracking catalyst, a second step in which the treated product from the first step is subjected to hydrodewaxing using a hydrodewaxing catalyst, and a third step in which the treated product from the second step is subjected to hydrorefining using a hydrorefining catalyst; and wherein said urea adduct value is measured as specified in the description; and wherein the content of the first lubricating base oil component is 50 to 90 % by mass, based on the total amount of the lubricating base oil, and the content of the second lubricating base oil component is 10 to 50 % by mass, based on the total amount of the lubricating base oil. a lubricating base oil, having a viscosity index of 100 or higher, an initial boiling point of not higher than 400°C, a 90% distillation temperature of 470°C or higher and a difference between the 90% distillation temperature and the 10% distillation temperature of at least a 70°C, wherein the initial boiling point, the 90% distillation temperature and the 10% distillation temperature are measured according to ASTM D2887-97, an ashless antioxidant containing no sulfur as a constituent element, wherein the content of the ashless antioxidant containing no sulfur as a constituent element is 0.01 to 5 % by mass, based on the total amount of the lubricating oil composition; and at least one selected from among ashless antioxidants containing sulfur as a constituent element, and organic molybdenum compounds, wherein the content of the ashless antioxidant containing sulfur as a constituent element is 0.001 to 0.2 % by mass in terms of the sulfur element, based on the total amount of the lubricating oil composition, and the content of the organic molybdenum compound is 0.001 to 0.2 % by mass in terms of the molybdenum element, based on the total amount of the lubricating oil composition; and a first step in which a normal paraffin-containing feed stock oil is subjected to hydrotreatment using a hydrocracking catalyst, a second step in which the treated product from the first step is subjected to hydrodewaxing using a hydrodewaxing catalyst, and a third step in which the treated product from the second step is subjected to hydrorefining using a hydrorefining catalyst; and