Distribution and features of POC in cultivating waters of Sanggou bay was discussed , according to the nine investigations from Nov .1993 to Oct .1994 .Horizontal distribution or season change of POC was remarkable , but vertical distribution change was not apparent .There was a positive linear interrelation between POC and Chl-a .It was agreeable to the research results of other seawaters that larger POCB/POC value always appeared when photoplankton rate growing faster .The retention period of POC in euphonic zone was estimated to 29 days .