Abstract: The growth characteristics of Penaeus japonicus released in the Guzhenkou Bay of Qingdao was studied in this paper. The result showed that the male grew more quickly than the female, but the female could reach bigger body sizes. The turning point of the weight growth curve for the female was about 91 days, and about 77 days for the male. We suggested that mid-September would be a preferred starting date for recapture. The optimal releasing date should be ahead of early June. Before mid-September, the released P. japonicus mainly distributed in the area within 5m isobaths and with the bottom of mud-sand.