To explore the changing patterns of the dietary habits and migratory patterns of the jumbo squid （Dosidicus gigas） and their potential relationship with abnormal climate events and variations in fishing intensity.In this study, we selected D.gigas from the Central Eastern Pacific Ocean as research object, and evaluated the sequentialstable isotope values of δ¹³C and δ¹⁵N in sectioned fragments of gladius. Using climate and environmental indices, the inter-annual variations in the ontogenictrophic patterns of the D.gigas were compared and their causes were explored.The results indicated that the δ¹³C values of 2019 D. gigasgladius significantly increased with individual growth, and the trophic niche narrowed, which may be related to the migration from equator to the southern hemisphere after the El Niño occurred. Differences were also found in the trophic patterns of the D.gigascollected in the La Niña periods, i.e., 2018, 2020, and 2021. In 2018, the δ¹³C and δ¹⁵N value of D.gigasgladius significantly increased with individual growth, indicating a southward migration to higher latitudes in the Southern Hemisphere. However, there was no significant change in the trophic niche, suggesting a relatively stable food source for D.gigas. During the implementation of seasonal moratorium in the high seas in 2020 and 2021, there were no significant changes in δ¹³C and δ¹⁵N values with individual growth, while higher trophic niche width during the later stages of life span. This indicated that these individuals had narrow migratory range, stabledietary, and high ecological resilience. These findings illustrate the sensitivity of D.gigas to abnormal climatic events and variation of fishing intensity. However, further research is needed to determine the extent of each factor's influence.