Based on data collected from four bottom trawl surveys conducted in the East China Sea（26°00′-33°00′N、120°30′-128°00′E）during autumn 1997, spring 1998, summer 1999 and winter 2000, the temporal\|spatial distribution of mature stock of T. pacificus was analyzed, and the relationships between the population maturity index (PMI) and environmental factors were examined by using a generalized additive model (GAM). The results indicated that the mature stock of T. pacificus was found in all seasons, with the highest value of PMI in autumn and the lowest in spring. The mature stock was mainly distributed in offshore of the East China Sea, where environmental conditions are influenced by both the Kuroshio Current and the Taiwai Warm Current. The environmental adaptation of mature stock of T. pacificus showed significant seasonal variations. The seasonal distribution patterns of temperature, salinity and water depth were 14.70-1830 ℃ in spring, 13.18-20.91 ℃ in summer, 13.96-24.67 ℃ in autumn, and 14.33-19.75 ℃ in winter; 2952-34.63 in spring, 31.57-34.27 in summer, 32.26-34.72 in autumn, and 34.25-34.70 in winter; and 55-179 m in spring, 43-176 m in summer, 40-184 m in autumn, and 79-152 m in winter, respectively. In summary, the temporal\|spatial distribution of mature stock of T. pacificus was characterized by a wide range of areas and multiple seasons. These distribution patters can reduce the competition among individual juveniles of T. pacificus and enhance the mature stock for reproduction.