The experiment was conducted to determine the effect of partial replacement of fish meal (FM) by corn gluten meal (CGM) on nitrogen and phosphorus retention of Carassius auratus gibelio. Two kinds of isonitrogenous, isocaloric diets were formulated to contain 0 (with 10% FM) and 8% of CGM respectively. Three sizes(initial weight of 26.90g, 51.70g, 97.67g) of Carassius auratus gibelio were fed for 97 days in cage culture, and sampled on 30th, 61th and 97th day. After feeding, nitrogen retention, phosphorus retention of muscle and glutamate dehydrogenase (GDH) activity of hepatopancreas and muscle were determined in different sizes of Carassius auratus gibelio in three feeding phases. The results showed that nitrogen contents of muscle inⅡand Ⅲ phases of small size,Ⅰphase of medium size and Ⅲ phase of large size were significantly, but the others were not significantly defferent between FM and CGM group; Phosphorus content of muscle inⅠandⅡ phases of small size were not significantly different except that phosphorus content of FM group were significantly higher than CGM group in Ⅲ phase (P<0.05), phosphorus content of CGM group were overall significantly higher than FM group in medium size and large size but Ⅲ phase of large size (P<0.05); Muscle nitrogen retention of FM group was significantly higher than CGM group (P<0.05) except forⅠphase of medium size; There were no significant differences on GDH activity of hepatopancreas with feeding; GDH activity of muscle of FM were not significantly different from CGM group without Ⅱ phase of medium size andⅠphase of large size; Phosphorus retention of muscle of CGM group was significantly lower than CGM group (P<0.05) withoutⅠphase. All results indicated that CGM group (replacing same amount of fish meal) reduced nitrogen and phosphorus retention in muscle of Carassius auratus gibelio compared with fish meal group and there was no significant effect on GDH activity of hepatopancreas and muscle. Protein catabolism was not significantly effected.