Abstract： Two experiments were conducted to investigate the effect of crystalline or coated amino acids on growth performance and serum free amino acids of allogynogenetic crucian carp. In Exp.1, five diets, including high or low fish meal diets (containing18% or 9% fish meal, respectively), low fish meal diet added with 0.23% Lys and 0.09% Met of crystalline, dextrin coated and starch coated styles, were designed to feed allogynogenetic crucian carp fingerling with initial body weight of 2.48g for 6 weeks. Growth rates of the five groups were 214.3%, 169.8%, 173.3%, 204.7%, 203.2% respectively. Compared with low fish meal control diet, there was no significant effect of adding crystalline amino acid on growth performance, but growth rate was improved by 20.5%, 19.7%( P <0.05) and feed coefficient was decreased by 0.40, 0.39(P <0.05) by adding dextrin or starch coated amino acid. In Exp.2, basal diet (6% fish meal) was added without or with 0.21% Lys and 0.08% Met of crystalline, dextrin coated and starch coated styles. Then serum free amino acids were determined 1, 3, 5, 12h after allogynogenetic crucian carp (body weight of 220g) intaking diets. Results showed that serum free amino acids absorbing peak value were advanced by adding crystalline amino acids, but delayed by adding coated amino acids compared with crystalline amino acid. Results above showed that crystalline amino acids’ absorbing velocity in digestive tract could be delayed and their availability improved by coating with dextrin or starch. Key words: allogynogenetic crucian carp; crystalline amino acid; coated amino acids; growth; serum free amino acid