A lubricating oil composition for internal combustion engines comprising a base oil, a thioheterocyclic compound represented by the following formula: (R 1) k - m -A S - n -(R 2) l wherein As represents a thioheterocycle; each of R 1 and R 2 represents a hydrogen atom, an amino group, a C1 to C50 hydrocarbyl group selected from among an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, and an aryl group, or, in the case of a hydrocarbyl group, a C1 to C50 heteroatom-containing group having an atom selected from among an oxygen atom, a nitrogen atom, and a sulfur atom, in the hydrocarbyl group; and each of k, 1, m, and n is an integer of 0 to 5, and an aminoalcohol compound having, in the molecule thereof, one or more amino groups and one or more hydroxyl groups, wherein the aminoalcohol compound contains at least one member selected from a compound represented by the following formula and a boronated derivative thereof: wherein each of R 3, R 4, and R 5 represents a hydrogen atom, an amino group, or a C2 to C38 hydrocarbyl group selected from among an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, and an aryl group, wherein the composition has a phosphorus content P, determined in accordance with JPI-5S-38-92, and a sulfated ash content M, determined in accordance with JIS K 2272, M and P being expressed in mass% based on the total amount of the composition, satisfying any of the following conditions A to C: condition A: P < 0.03, and M < 0.3; condition B: P < 0.03, and 0.3 ≤ M ≤ 0.6; and condition C: 0.03 ≤ P ≤ 0.06, and M < 0.3. each of R 1 and R 2 represents a hydrogen atom, an amino group, a C1 to C50 hydrocarbyl group selected from among an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, and an aryl group, or, in the case of a hydrocarbyl group, a C1 to C50 heteroatom-containing group having an atom selected from among an oxygen atom, a nitrogen atom, and a sulfur atom, in the hydrocarbyl group; and each of k, 1, m, and n is an integer of 0 to 5, and an aminoalcohol compound having, in the molecule thereof, one or more amino groups and one or more hydroxyl groups, wherein the aminoalcohol compound contains at least one member selected from a compound represented by the following formula and a boronated derivative thereof: wherein each of R 3, R 4, and R 5 represents a hydrogen atom, an amino group, or a C2 to C38 hydrocarbyl group selected from among an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, and an aryl group, wherein the composition has a phosphorus content P, determined in accordance with JPI-5S-38-92, and a sulfated ash content M, determined in accordance with JIS K 2272, M and P being expressed in mass% based on the total amount of the composition, satisfying any of the following conditions A to C: condition A: P < 0.03, and M < 0.3; condition B: P < 0.03, and 0.3 ≤ M ≤ 0.6; and condition C: 0.03 ≤ P ≤ 0.06, and M < 0.3. wherein the composition has a phosphorus content P, determined in accordance with JPI-5S-38-92, and a sulfated ash content M, determined in accordance with JIS K 2272, M and P being expressed in mass% based on the total amount of the composition, satisfying any of the following conditions A to C: condition A: P < 0.03, and M < 0.3; condition B: P < 0.03, and 0.3 ≤ M ≤ 0.6; and condition C: 0.03 ≤ P ≤ 0.06, and M < 0.3.