A lubricating oil composition used in an internal combustion engine is provided. The internal combusting engine uses a fuel that contains at least one fat and oil selected from a group consisting of natural fat and oil, hydrotreated natural fat and oil, transesterified natural fat, and oil and hydrotreated transesterified natural fat and oil. The lubricating oil composition includes: base oil of lubricating oil; a component (A) containing a boron derivative of an alkyl or alkenyl-substituted succinimide compound having a number average molecular weight of 200 to 5000; and a component (B) containing an alkaline earth metal-based detergent. The component (A) is contained by 0.01 to 0.2 mass % in terms of boron of a total amount of the composition while the component (B) is contained by 0.35 mass % or less in terms of the alkaline earth metal of the total amount of the composition.