Abstract: By monitoring the water quality and heavy metal content in sea cucumber Apostichopus japonicus in a aquatic breeding farm in Penglai, the author analyzed the content changes inorganic nitrogen, phosphorus and heavy metal in water of different conditions, then the heavy metal content was detected in A. japonicus of different specifications, and the effect of artificial breeding of A. japonicus on water quality and accumulation of heavy metals were also discussed. The results showed that in the breeding process, accumulations of ammonia and nitrate were not obvious, but nitrite and inorganic phosphorus were accumulated rapidly. N/P value varied greatly in water of different conditions, the highest value (50.62) was found in sand-filtered reservoir water (P<0.05), and then decreased gradually with the process of breeding, reached 2.48 before changing ponds. The contents of Zn were the highest in A. japonicus of all three specifications compared with the other metal elements, while the bioconcentration factors (BCFs) of Cd were much higher than other elements; The content (0.226 mg/kg) and BCF (0.22) of Pb were both the highest in overwintering large individual A. japonicus, but those of the other elements were at generally lower levels. In different breeding periods, BCFs of metal elements varied to some extent. BCFs in spring seedling were ranked as follows: Cd>Cr>Cu>Pb>Zn, BCFs in overwintering small seedling were ranked as follows: Cd>Cr>Cu>Zn>Pb, BCFs in overwintering small seedling were ranked as follows: Cd>Pb>Cr>Cu>Zn. The study could be applied in many aspects of sea cucumber seedlings and regulation of breeding environment, in order to promote environmental safety of sea cucumber seed breeding, provide a reference for the entire intensive aquaculture regulation and management of the water environment, and further promote marine economy healthy and sustainable development.[Chinese Fishery Quality and Standards, 2014, 4(4):27-32]