To analyze the long-term characteristics of changes in the structure of the fishery ecosystem in the FAO 77 fishing area of the Eastern Central Pacific （ECP）， this study utilized fishery catch data from the ECP FAO 77 area from 1950-2019. Combining multivariate statistical analysis methods， specifically Principal Component Analysis （PCA） and Sequential T-test Analysis of Regime Shifts （STARS）， we identified the regime shift time points for ecosystem functional groups， thermal adaptation groups， and representative indices （Mean Trophic Level， MTL； Mean Suitable Temperature， MST； and Species Evenness， EVE）. The results indicate that the structure of the ECP fishery ecosystem exhibits significant decadal changes， with regime shift nodes primarily concentrated in the late 1950s and mid-1970s. The regime shift occurring in the late 1950s was characterized by an increase in the catches of functional groups such as benthic fish， reef-associated fish， cartilaginous fish， and invertebrates. This was accompanied by a rise in the catches of warm-water species， leading to an increase in the ecosystem's Mean Trophic Level （MTL） and Species Evenness （EVE）， reflecting the utilization of diversified resources during the early stage of fishery development. Another pivotal shift occurred in the mid-1970s. At this time， there was a significant increase in the catches of pelagic fish and cartilaginous fish， while catches of cold-water species also increased. However， the ecosystem's Mean Trophic Level （MTL）， Mean Suitable Temperature （MST）， and Species Evenness （EVE） showed a declining trend. The study indicates that the structure of the ECP fishery ecosystem underwent two major regime shifts over the past 70 years， and the interactive effects of climate change and human fishing activities were key drivers shaping its evolutionary trajectory. This study provides a scientific basis for analyzing the dynamics of the ECP fishery ecosystem and formulating adaptive management measures.