Trawling surveys showed that the young Penaeus chinensis Shrimp in Jiaozhou Bay were congregated during July-august in its western part. August 1981-August 1994 water temperature, salinity, nutrient salt showed no distinctive changes in the ecological environment of Jiaozhou Bay.Where the decreasing number of young shrimp which is largely due to the enhanced catch capability that decreased parent shrimp density to 15-20 ind/k㎡, and other anthropogenic factors adversely larva and young shrimp growth, all of which have caused the average annual catch to be 14-335 ind/h only.