A lubricating oil composition for internal combustion engines, containing a base oil, (A) at least one compound selected from disulfide compounds represented by the following general formula (I): R1OOC-A1-S—S-A2-COOR2  (I) and disulfide compounds represented by the following general formula (II): R7OOC—CR9R10—CR11(COOR8)—S—S—CR16(COOR13)—CR14R15—COOR12  (II), (B) an organomolybdenum compound, and (C) a phenol-based antioxidant and/or an amine-based antioxidant. The lubricating oil composition is a low ash, low phosphorus lubricating oil composition which is used for internal combustion engines such as gasoline engines, diesel engines and gas engines, which has improved oxidation stability and friction reducing effect, and which complies with environmental regulations.