A water-cooled air conditioning system includes an indoor unit having a first heat exchanger where air and refrigerant are heat-exchanged with each other, an outdoor unit having a second heat exchanger where water and the refrigerant are heat-exchanged with each other, a cooling tower for cooling the water directed to the second heat exchanger, a discharge duct for guiding the air conditioned in the indoor unit to an indoor space for an air conditioning, and an intake duct for guiding the air in the indoor space to the indoor unit. The second heat exchanger is a plate type heat exchanger having a space that is divided into a plurality of sections along which the refrigerant and the cooling water separately flow.