A CO2 recovery system includes an absorption tower and a regeneration tower. CO2 rich solution is produced in the absorption tower by absorbing CO2 from CO2-containing gas. The CO2 rich solution is conveyed to the regeneration tower where lean solution is produced from the rich solution by removing CO2. A compressor compresses CO2 that is removed from the rich solution and discharged through a head of the regeneration tower. Heat is generated while the compressor compresses the CO2. A heat supplying unit supplies the heat to the regeneration tower for heating the lean solution.