In Jeju Island, red sea bream is mainly caught by long line with a live squid as bait. The movements of artificial jigs in the fishery are supposed to be an important factor for catching the target organism as well as bait. To develop new fishing method for long line fishery, movements of the bait which was squid were tried to be characterized. In a water tank experiment, a live squid was hooked by a fish hook attached to a model long line. And then movements of squids in the water tank were recorded for 20 minutes by a video camera. Recorded movement of the squid was just periodically up-and-down moving, with a dominant frequency of 0.125Hz, and amplitude of 10.8cm.