The adults and larvae of Nereis are the bait of economic fish and shrimp. Residents along the southern coast of China and Southeast Asia all have the habit of eating nereis. Nereis and Perinereis multidentata often live in rice fields and gnaw at rice roots. Nereis digging holes in salt fields will overflow brine, which is a kind of harm to salt industry. Nereis is also an important experimental material for teaching and scientific research. College animal teaching needs a large number of nereis as representatives every year to understand the system and structure of higher invertebrates. Another example is the infiltration mechanism of nereis to fresh water; The relationship between brain hormones and sexual maturity of Nereis: the development and settlement of Nereis larvae: the relationship between Nereis and the environment is a research topic in physiology, developmental biology and ecology. Therefore, Nereidae are extremely important marine and brackish water organisms.