This paper report s the feeding habits of Mystus guttatus in the Pearl River with natural resources investigation. The reports include feed fullness, feed composition, frequency of feed occurrence and variation of feed composition in dif ferent seasons was also studied. The investigation result shows that the feed of Mystus guttatus in the Pearl River are crustaceans, insect, annelida, f ish and pieces of plant . Among them, the crustaceans and insect s are the main feed, the emergence frequency is 78. 6% and 45. 8% respectively. In different seasons, the variety of feed composition is markedly different , and no pause of feeding. The feed of Mystus guttatus changed with the different body length of the fish. The first feed change period was at about 170mm body length and the second at about 240mm body length. It is getting simpler as Mystus guttatus grows up.