The present invention is a natural circulation type cold and hot water heat exchanger for simultaneous breeding of cold and hot water type fish species that enable both cold and hot water types to be raised simultaneously by using a natural circulation method of cold water and hot water heat exchange method in cultivating fish species. Regarding the system, the high-temperature and high-pressure refrigerant gas is heat-exchanged in the condensed hot water heat exchanger 200 in the compressor 100, and then the condensed liquid is expanded through the receiver tank 210 through the filter dryer 220 and the solenoid 230. The low-temperature refrigerant gas from the valve 240 is sent to the evaporative cold water heat exchanger 300 and the refrigerant gas is circulated to the compressor 100 through the liquid separator 310 and the suction strainer 320, and the condensed hot water heat exchanger ( The hot water of 200) is sent to the hot water heat storage tank 400 and circulated from the hot water heat storage tank 400 to the circulation pump 410 through the filter 420 to the condensed hot water heat exchanger 200. The hot water is sent to the heat exchanger 510 of the filtering device 500 by the circulation pump 430, and the hot water of the filtering device 500 is supplied to the hot water culture tank 10 by the circulation pump 520, and the hot water culture tank ( The aquaculture water of 10) was sent to the filtering device 500 through the water outlet line 12 installed with the water outlet valve 11, and circulated from the filter device 500 to the hot water storage tank 400 through the water outlet line 440. The cold water of the evaporative cold water heat exchanger 300 is sent to the cold water storage tank 600 by the circulation pump 340 and circulated from the cold water storage tank 600 to the evaporative cold water heat exchanger 300 through the filter 620. The cold water of the heat storage tank 600 is sent to the heat exchanger 710 of the filtering device
