Abstract: Two experiments were conducted at 20℃ to study the growth rate, ammonia excretion and phosphate excretion by the ornamental goldfish, Carassius auratus (L.). In experiment A, minced beef was used as food. In experiment B, a dry pellet diet was used as food. Fish were tested at six ration levels in each experiment. The relationship between specific growth rate (SGR) and ration (R) can be described by the equation: SGR=a+bln(R+1). When ration was expressed on a dry weight basis, food type did not have significant effects on the coefficients in the above equation. The relationship between ammonia excretion (NE) and nitrogen intake (NI) was: NE=a+bNI. Food type did not have a significant effect on the sope in the above equation, but there was a siginificant difference in the ammonia excretion rate, adjusted for an average rate of nitrogen intake, between the two experiments. The relationship between phosphate excretion (PE) and phosphorus intake (PI) was: PE=a+bPI. Food type did not have a singificant effect on the slope in the above equation, but there was a sinificant difference in the phosphate excretion rate, adjusted for an average rate of phosphorus intake, between the two experiments. Despite the significant differences between the experiments, nitrogen intake and phosphorus intake could explain 98.0% and 75.7%, respectively, of the variance in the ammonia excretion and phosphate excretion in the combined data.