Twelve different diets with four calcium supply levels and three phosphorus supply levels were prepared for an 8-week feeding trial, which was conducted to investigate the effects of dietary calcium and phosphorus levels on growth, body composition and digestive enzyme activities of juvenile discus fish. The result at the end of the experimental showed that:the survival rate significantly reduced with the rise of dietary phosphorus supply. As 0.5% or 1.0% phosphorus supplied, the specific growth rate of weight (SGRW) sharply declined with the rise of dietary calcium level. Without calcium supplementation, the SGRW showed an obvious increase with phosphorus addition, but no significant difference was found between the two groups fed diets with 1.0% and 0.5% phosphorus supply. The specific growth rate of length (SGRL) significantly declined with the rise of dietary calcium supply. Fish fed diet with 1.0% phosphorus and without calcium supplementation showed the highest SGRL value and lowest length/height ratio. Dietary calcium or phosphorus supply showed significant effect on moisture, crude protein, crude fat and ash content of whole fish. Both protease and lipase specific activities of intestinal tract significantly reduced with the rise of dietary calcium supplementation. Individual phosphorus or calcium supply did not affect the specific activity of amylase while an obvious interaction was found between calcium and phosphorus. In presence of 1.0% phosphorus supplied in diets, amylase activity increased first with rising Ca level, followed by a reduction. Dietary calcium and phosphorus levels also showed an interaction on glutamic-pyruvic transaminase (GPT) activity, and individual calcium supplement showed a significant reduction on GPT activity without phosphorus supply. In summary, 0.5% phosphorus added without calcium was optimal for the growth of juvenile S. haraldi.