An energy saving system utilizing temperature sensing flow control valve to realizing chilled water loop is provided, which includes an air blower, a temperature sensing flow control valve and a temperature setter. The air blower is disposed in the chilled water loop of a building to chill the air by the chilled water loop and then discharge the chilled air from the air outlet of the air blower. The valve is connected to a chilled water outlet beside the air blower and controls the flow of the chilled water flowing from the air blower to the chilled water loop. The temperature setter is connected to the valve and detects the temperature of the air discharged from the air outlet; the temperature setter opens or closes the temperature sensing flow control valve according to the detected air temperature and adjusts the flow of the chilled water by the valve.