To provide a lubricating oil having suitable compatibility and solubility toward a hydrocarbon coolant and/or HFC coolant, further minimizing the sedimentation of a solid material at low temperatures, especially reducing the abrasion of a sliding part of a compressor for improving endurance.

This lubricating oil composition uses a hydrocarbon coolant comprising esters obtained by mixing 10-60 wt.% ester of pentaerythritol with 2-ethylhexanoic acid, 10-50 wt.% ester of neopentyl glycol with 2-ethylhexanoic acid and 20-60 wt.% ester of pentaerythritol with a mixture of 2-ethylhexanoic acid and 3,5,5-trimethylhexanoic acid at (3/7)-(7/3) mixing weight ratio, and having 10-50 mm2/s dynamic viscosity at 40°C, and/or a hydrocarbon coolant obtained by substituting a part of hydrogen with fluorine.