Tilapia lives in the middle and lower layers and is an omnivorous fish with plants as its staple food. Tilapia can't tolerate low temperature, and it will freeze to death when the water temperature is about 10℃. Monocultured tilapia can put 3,000-5,000 fish with a size of 3 cm per mu in a pond with a water depth of 1 m, and the yield can reach 300-400 kg. Polyculture can be divided into two forms: mainly tilapia and mainly tilapia supplemented by tilapia. 2,500 tilapia (3-5 cm) are stocked in adult fish ponds with tilapia as the main species, and the breeding specifications can reach 1.80-200g/ fish. Raising tilapia in ponds dominated by domestic fish can increase the yield by 10%-20%. Adult tilapia mainly feed on plankton and organic debris, so the water quality should be fertile whether it is raised alone or mixed with domestic fish. By fertilizing and cultivating water quality, the water is rich in biological bait. Generally, manure 100- 150 kg or green manure 200-300 kg per mu is applied every week.