Abstract: There is disclosed a lubricating oil composition for automatic transmissions which comprises a base oil comprising at least one oil selected from the group consisting of a mineral oil and a synthetic oil each having a specific kinematic viscosity and a % CA; (A) a non-boron based succinic acid imide (e.g. polybutenylsuccinic acid imide) and a boron based succinic acid imide each in an amount of 0.1 to 5% by weight based on the whole composition; (B) a condensation product of a branched chain fatty acid having 8 to 30 carbon atoms (e.g. isostearic acid) and an amine (e.g. tetraethylene-pentamine) in an amount of 0.05 to 2% by weight based on the same; and (C) a dialkyl hydrogenphosphite (e.g. dioleyl hydrogenphosphite) in an amount of 0.1 to 1% by weight based on the same, and optionally at least one member selected from viscosity index improvers, antioxidants, metal deactivators, defoaming agents, detergents, extreme pressure agents and rust preventives.