The study on the respiration and production of bacterioplankton in five shrimp cultural enclosure ecosystems showed that the production and respiration fluctuated from 90 to 909 and 248 to 1785 μgC·L -1 ·d -1 , respectively. There existed a significant positive relationship between production and respiration. The daily P/B ratio of bacterioplancton averaged 0.93 d -1 , and its production efficiency averaged 0.34.