To discussion the yellowfin tuna migration behaviors in the difference of waters, using the ultrasonic tag to tagging of yelowfin tuna in this study. Collected the zooplankton on the DSL layer, and observe the yellowfin tuna stomach content , to discussion the yellowfin tuna migration behavior and DSL layer of relations moved with zooplankton. The pop-up satellite archival tag to tagging adult yellowfin tuna in the southwestern waters of Taiwan, will establish yellowfin tuna migration route.