In 2010—2011,active Antarctic krills(Euphausia superba)which survived and were collected immediately in the capture by a pelagic trawl with the factory trawler “Anxinghai” near South Orkney Island and were transferred to a test tank and their behaviors were observed.45 Antarctic krills were observed during the experiment,and the body length were 37-55 mm,the light intensity of water surface in test tank was kept at 220 lx, and the temperature of the water in test tank was constant at 0 ℃.The whole experiment lasted for 13 days.There are three results obtained from the experiment:(1) Body color of Antarctic krill changes rapidly after being put into test tank under lighting;(2) In static condition,Antarctic krill almost keeps in the same position in corners.When they moved,they could swim from one corner to a neighbor corner along the wall of the tank,and a few times to swim with a higher speed across the center of the test tank;In hydrodynamic conditions,they can swim against the current and aggregate to a schooling at a velocity about 0.5 m/s,schooling vanished while current is greater than 1 m/s;(3) Antarctic krill molted during the experiments,and the average body length increased about 5-8 mm.