Chub mackerel (Scomber japonicus) is one of the important pelagic fishery resources in the China's coastal waters. It is needed to standardize the catch per unit effort (CPUE) in the stock assessment. Many factors including seasonal, regional and marine environmental conditions affect the CPUE. In this paper, generalized linear model (GLM) and generalized additive model (GAM), by which temporal, spatial, environmental, and fisheries vessels variables were chosen for analysis, were used to standardize CPUE of chub mackerel for Chinese large lightingpurse seine fishery in the East China Sea and Yellow Sea from 1998 to 2006, and evaluate impacts of environmental variables on CPUE. Firstly, GLM was applied to evaluate impacts of temporal, spatial, environmental, fisheries operational variables on the CPUE, and the significant factors. Then the significant variables were used in the GAM one by one to select an optimal GAM by using the Akaike Information Criterion (AIC). The derived GAM was used to quantify the effects of temporal, spatial, environmental, and fisheries operational variables on the Chub mackerel catch rates and to derive standardized CPUE. The GLM analysis revealed the importance of eight variables ranked by decreasing magnitude: Year, Fleet, Fleet×Year, Month, Fleet ×Month, Longitude, Latitude and Sea surface temperature. The final GAM including eight significant variables derived from GLM analysis was the optimal model based on AIC and explained 27.78% of the variance in nominal CPUE. GAM analysis indicated that high CPUEs were found in the central East China Sea at sea surface temperatures ranging from 28 to 31 ℃ in summer and in the Yellow Sea at sea surface temperatures from 12 to 16 ℃ in winter. The standardized CPUE tended to decrease from 1998 to 2006, which might result from increased fishing efforts.