A polycarbonate lubricating oil composition which is resistant to decomposition of the polycarbonate and the generation of carbon dioxide gas. The lubricating oil composition contains a polycarbonate lubricant, at least one compound selected from the group of epoxy compound, phenol compound, sulfur compound and amine compound, and optionally a triester phosphite or a triester phosphate compound as inhibitors to the generation of carbon dioxide gas. The lubricating oil composition are stable, have excellent lubricating properties, cleaning properties, and electrical insulating properties, and their viscosity at low temperature can readily be lowered.