The yellow goosefish (Lophius litulon), a demersal fish, is distributed in the Western Pacific, including the East China Sea, Yellow Sea, Bohai Sea, Japan and Korean waters. It is a cold-temperate species, typically captured at depths of 40-90 meters in a temperature range of 11-14 degree. In recent years, since traditional fishery resources have been overexploited, yellow goosefish has become an important fishery resource in China. It is mainly harvested by mobile stow net along the South Yellow Sea. Its yearly average yield is about 12 thousand tones in the Jiangsu and Zhejiang provinces. However, there have been little studies on this species, especially on its feeding ecology. Previous studies indicated that Lophius litulon has a trophic level of 3.66, meaning that it is one of the top trophic level fish species in the East China Sea and Yellow Sea. It feeds on various commercially targeted fish species, and this may have potential effects on these fish species and fisheries. This paper attempts to study the feeding ecology of Lophius litulon by analyzing stomach contents based on monthly samples collected from the South of the Yellow Sea from September 2008 to July 2009. The preliminary results reveal that the diet of Lophius litulon varies with fish as the dominant prey species. It makes up 83.44% of the total food weight, including Larimichthys polyactis, Chaeturichthys stigmatias, Apogon lineatus, Trichiurus japonicus, Harpodon nehereus, Trachypenaeus curvirostris and Engraulis japonicus. Crustacea and cephalopoda account for 12.45% and 4.23%,respectively. Larimichthys polyactis is the most important prey species for Lophius litulon through the year and all size groups, comprising 33.05% of the total food weight. Apogonichthys lineatus is the most common species and has the largest number in yellow goosefish stomach. The diet composition varies a lot seasonally, particularly for Engraulis japonicus, which consists of 25.52% of the total food weight in winter but disappears in spring. Furthermore, feeding intensity also shows significant seasonal variation and changes in body length. The feeding intensity is maximized in winter and minimized in spring, it is thought to be related to the reproduction strategy, as winter is its pre-spawning period and spring is its spawning season. The individuals less than 100mm in body length have the largest feeding intensity and more than 500 mm have the lowest, which may result in different growth in different development stages. The cluster analysis shows that Lophius litulon changes feeding habits when its total length arrives at 100mm. The larvae below 100mm in body length primarily feeds on Chaeturichthys stigmatias,while adult fish larger than 200mm in body length prefer Pseudosciaena polyactis. However, the findings in this paper differ from other studies partially due to different sampling areas. As a non-selective predator, Lophius litulon feeds on different species in different areas, depending on the prey′s availability.