The feeding habits of Pacific bluefin tuna, Thunnus orientalis were analyzed using samples by large purse seine fishery in Korean waters from 2012 to 2017. The number of samples was 1,274 and the fork-length (FL) ranged from 34.6 to 218.0 cm. According to %IRI, the Important main prey items of immature individuals (below 91.4 cm in FL) were Pisces, Cephalopoda and Euphausiacea and those of mature individuals were Cephalopoda and Pisces. T. orientalis showed ontogenetic changes in prey item that Pisces was dominated in size class of 30-89 cm (FL), Cephalopoda in 90-179 cm (FL), and Pisces above 180 cm. As for seasonal changes in prey item, Cephalopoda was dominant in spring and Pisces was dominant in summer, autumn and winter. %F, %N, %W and %IRI cluster analysis divided area into three groups: Group A was dominated by Pisces; Group B was dominated by Cephalopoda, and Group C was dominated by Euphausiacea.

서 론
 재료 및 방법
 결 과
  표본의 체장조성
  위 내용물 조성
  Cluster 분석에 의한 그룹핑
 고 찰
 결 론
 References

• 조헌주(국립수산과학원 원양자원과) | Heon Ju Jo (Distant Water Fisheries Resources Division, National Institute of Fisheries Science)
• 이성일(국립수산과학원 원양자원과) | Sung Il LEE (Distant Water Fisheries Resources Division, National Institute of Fisheries Science) Corresponding author
• 김두남(국립수산과학원 원양자원과) | Doo Nam KIM (Distant Water Fisheries Resources Division, National Institute of Fisheries Science)
• 이미경(국립수산과학원 원양자원과) | Mi Kyung LEE (Distant Water Fisheries Resources Division, National Institute of Fisheries Science)