Abstract:The seasons of autumn and winter are the main fishing time of Trachurus murphyi. It has practical meaning to establish the forecasting model of fishing grounds for T. murphyi. In this paper, we established the habitat suitability index of T. murphyi during autumn and winter based on Chinese commercial fishing data of T. murphyi in Southeast Pacific during May to September from 2003 to 2009 and combined with oceanic environmental data including sea surface temperature (SST) and sea surface height (SSH). The fishing effort and CPUE are considered as the indicator of suitability index (SI), and the curves of SI were estimated by using the method of Data Envelopment Analysis. And the Arithmetic Mean Model (AMM), Geometric Mean Model (GMM) and the weighted AMM are used to establish the integrated habitat suitability index (HSI). The fishery data in 2010 and 2011 are used to compare and test the HSI model. The results indicated that the SI curve based on fishing effort is better than that based on CPUE, and the AMM is better than that the GMM. The weighted AMM is also more suitable than the general AMM, and the monthly suitable weight of SST during May to September is 0.4, 0.7, 0.5, 0.7 and 0.1, respectively. In 2010 and 2011, in the fishing areas with greater than 0.6 of HIS, the percentages of catch and fishing effort attained 75%-93% and 80%-90% respectively. It is concluded that the habitat suitability index during May to September based on fishing efforts by using external envelope method with monthly weights of SST could be used to predict the fishing ground of T. murphyi. In different months, SST and SSH have different effects on fishing ground of T. murphyi during autumn and winter.