Based on the survey data of bottom trawl fishery resources in Zhoushan fishing grounds and adjacent sea areas in spring (April) and autumn (November) from 2016 to 2019, we analyzed the spatial and temporal distribution characteristics of biomass resource density of small yellow croaker (Larimichthys polyactis) in this sea area, and used two-stage generalized additive model to study the environmental factors affecting its spatial and temporal distribution. The results showed that the density of small yellow croaker resources showed obvious seasonal changes, and it was significantly higher in spring than in autumn. The main factors affecting the resource density of small yellow croaker in this sea area are season, water depth and bottom water temperature. Small yellow croaker is mainly distributed in the range of 19 to 66 m water depth and the range of 11?22 ℃. With the increase of water depth, the resource density of small yellow croaker shows an upward trend, and the resource density is the highest near the water depth of 60 m. The resource density showed a downward trend at 16 ℃ centigrade to 20 ℃, and the resource density was high at 12?16 ℃. This result reveals the influence of seasonal variation of water depth and bottom water temperature in the sea area on the density distribution of small yellow croaker resources, and provides basic data for further understanding of its spatial distribution and quantitative management of resources.