This research want to understand of the resource situation of the swordtip squid, Uroteuthis (Photololigo) edulis, in Northern Taiwan included species, spawning ground, and migration route. On the other hand, we will evaluate the possibility of using sidescan sonar to monitor the resource fluctuation. We want to find the swordtip squid spawning ground in Northern Taiwan and to understand the temporal and spatial variation of swordtip squid population.