To study the influence mechanism of marine environmental factors on the potential fishing ground for Pacific saury in Northwestern Pacific, by using the fishery statistics data of Chinese Pacific saury fishing boats from 2013 to 2014 and the marine environment data of NOAA website, this paper set up MAXENT models: the accuracy of the MAXENT model was verified by using receiver operating characteristic(ROC) curve, the importance of oceanographic environmental factors was evaluated by Jackknife Method, the potential fishing area distribution map of the Pacific saury was made by Arcgis. The results show that MAXENT model was proved to be accurate and reliable: during the Pacific saury’s best fishing period from August to October, the potential fishing ground mostly occurred around the eastern waters of Hokkaido and Kuril islands .The fishing ground distribution for Pacific saury is influenced by SST mostly among several environmental factors, of which the average percentage contribution to the model is 64.3%,in the meantime, the average contribution percentage of chlorophyll (Chl.a) and slinity (SSS)are 20.6%, 15.2% respectively.In August and September, chlorophyll (Chl.a) holds a higher model contribution to the distribution of the Pacific saury than salinity (SSS),whereas, the effect of chlorophyll (Chl.a) on the distribution of Pacific saury in October was lower than salinity (SSS).