Abstract: Adding different quantity of rare earth nitrate to the Carassius auratus feed and researching the effect of rare earth on the production performance and nutritional status of Carassius auratus. The result indicates that the effect of adding rare earth nitrate 45mg/kg in the feed was the most obvious, the growth velocity was improved, the feed coefficient was greatly decreased significantly(p﹤0.01), the disease resistance ability was enhanced and the mortality rate was reduced, meanwhile the contents of protein and fat in bodies of fish was obviously improved(p﹤0.05).