Abstract: An eight-week net pen experiment was conducted to evaluate the potential to replace fish meal with three oil seed meals, soybean meal, rapeseed meal and cottonseed meal, in diets for 11.3 g sutchi catfish (Pangasius sutchi). Seven isonitrogenous and isocalific diets were established. The control diet was formulated to contain 45% fish meal, whereas in the other six diets, soybean meal was added at 31% and 46% to replace 50% and 75% of the fish meal, or rapeseed meal added at 20% and 40% to replace 25% and 50% of the fish meal, or cottonseed meal added at 19% and 39% to replace 25% and 50% of the fish meal. Results of the experiment indicated dietary fish meal level could be reduced from 45% to 23% by adding soybean meal at 31%, or from 45% to 34% by adding rapeseed meal at 20% or cottonseed meal at 19%, without significantly negative effects on survival, feed intake, weight gain, specific growth rate (SGR), feed conversion ratio (FCR), protein retention efficiency, viscerosomatic index and haematocrit value (Hct). Feed intake, weight gain and SGR significantly decreased when dietary fish meal level was reduced to 11% by adding soybean meal at 46%. Reducing fish meal level to 23% by adding rapeseed meal at 40% resulted in the increase of FCR and decrease of energy retention efficiency, while reducing fish meal level down to 23% by adding cottonseed meal at 39% resulted in the decrease of weight gain, SGR and Hct. These results suggest fish meal level in sutchi catfish diets could be reduced to 23% by using soybean meal (added at 31%), and to 34% by using rapeseed meal (added at 20%) or cottonseed meal (added at 19%), as fish meal substitutes.