||The jumbo (or Humboldt) squid, Dosidicus gigas, is a large pelagic ommastrephid squid which distributed in the Eastern Pacific Ocean (EPO). The jumbo squid is an important component of its ecosystem in the EPO and is the main target of squid fisheries in this region. The central challenge for fisheries ecology is to understand the abundance variations of resources under fishing pressure and its synergistic effects to the ecosystems. The jumbo squid fishery in Taiwan is not dominant in context of production or values, while it could act as a substitute for Illex argentious fishery and the jumbo squid has been a target species of SPRFMO. Therefore, it is essential to understand its population dynamics, environmental influences and fisheries management. The purposes of this projects are: (1) to explore the spatial distribution pattern of jumbo squid; (2) to analyze the CPUE variations and effects of environmental variables by GAM; (3) to estimate the population size and proportional escapement by depletion method ;(4) to maintain the database of catch and effort data of jumbo squid fishery. The working items are, 1) Re-arrange the dataset of jumbo squid in a monthly basis with a spatial resolution of 0.5 degrees. 2) Explore the spatial distribution patterns by GIS tools. 3) Analyze the CPUE variation by GAM with temporal, spatial and environmental variables. 4) Estimate initial population size and catchability coefficient by depletion methods. 5) Maintain and update fisheries data in 2011. The expected results are, 1) Understand the spatial distribution patterns of squid stocks. 2) Understand the CPUE trend and influences of environmental variables. 3) Understand the stock status and the exploitation rate.