Abstract: In order to explore a seawater ecological polyculture model, three culture objects of Seepweed （Suaeda glauca Bunge）, black sea bream （Sparus macrophslus） and Philippine clam（Ruditapes philippinarum）were selected. By setting up seepweed-philippine clam, seepweed-black sea bream, seepweed-black sea bream-philippine clam and black sea bream-Philippine clam four types of polyculture models （black sea bream fry breeding density is 155 fish/m³, Philippine sea clam culture density is 75 ind./m²） with the water quality ind.icators and cultivation of each system monitoring during the breeding process, we try to explore the characteristics of each model. The results showed that the seepweed-black sea bream system and the Seepweed-Philippine clam system have strong water self-purification ability. The ammonia nitrogen, phosphate, and nitrite nitrogen contents of the water body all show a downward trend in the later stage of the experiment, and the two systems show better results. However, the water quality ind.ex of the two systems of Philippine clam and black sea bream polyculture was poor, the mortality of the breeding subjects was high and the system lacks stability. The black sea bream of 155 fish/m³ and Philippine curtain clams of 75 ind./m² density were suitable for the establishment of Seepweed-black sea bream or Seepweed-Philippine clam polyculture model. Seepweed in the system can not only play a role in purifying water, but also increase the dissolved oxygen content of aquaculture water, and stabilize the pH of aquaculture water.

Key words: Suaeda glauca Bunge, Sparus macrophslus, Ruditapes philippinarum, ecological polyculture, water quality