A circulating culture system includes a culture pool, a water-purification tube structure, a first contamination-draining device and a filter device. The water-purification tube structure is disposed in the culture pool and has a plurality of water-inlet holes, and the first contamination-draining device is disposed in the culture pool. The filter device connects a water inlet tube and a water outlet tube. The water inlet tube is connected to the first contamination-draining device, and the water outlet tube is connected to the water-purification tube structure. The water inlet tube is disposed on a position higher than the water outlet tube.一種循環式養殖系統包括養殖池、淨水管路結構、第一排污裝置以及過濾設備。淨水管路結構配置於養殖池中並具有多個進水孔，第一排汙裝置設置於該養殖池中，過濾設備連接有連通於第一排汙裝置的進水管路與連通於淨水管路結構的出水管路，且入水口的高度高於進水口的高度。
