The movement and distribution of Penaeus orientalis, which werereleased in Xiangshan Bay of Zhejiang province, reside in both the same ehara-cteristics as in their original place, the Huanghai sea and Bohai sea, and specia-lities due to different geographical topography and ecosystematic environment.first, the released shrimp migrate from near shore water to off shore water,with only a few of them moving irregularly Secondly, all of them migrate to-wards the bay. There are three periods for these inhabiting ones, rig, seeking forfood in shallow water of near shore,growing in off shore water and flowing outof the bay. Most of them move in the neighbourhood_ of 10 m isobath line whenonce they flow out, with a majority of them alongside northern coast, The shrimpoutflow when tide ebbs and few of them come back again. This situation becomeworse at the time of big tide. The movement and distribution are affected by anyof or a combination of following factors, such as growth and density of shrimp,water temperature, baits,topography, wind and tide etc;and the most nportantfactor is shrimp growth. Torrential ebb tide and its non-strong circulation acce-lelate the outflow,with strong tropical typhoon, possibly incurring shrimp out-flow.