The present study has been conducted to investigate the effect of dietary total sulpher amino acids and copper administration on growth performance and some blood biochemical parameters of Japanese quail. A 3x3 factorial design was performed including three levels of total sulpher amino acids (TSAA) (0.75, 0.85 and 0.95%) and three levels of copper (CuSo₄) supplementation (0,100 and 200 mg/kg diet) throughout the growing period (1-6 weeks of age). A total number of 405 unsexed one week old Japanese quail chicks were randomly distributed into nine treatment groups of 45 chicks each with 3 replicates of 15 chicks each. Chicks of all experimental groups had nearly the same initial average body weight and were not statistically different. Growth performance traits (live body weight (LBW), body weight gain (BWG), feed intake (FI) and feed conversion ratio (FCR)) were studied throughout the growing period. Results obtained indicated, significant (P>0.01) improvement in LBW at 6 weeks of age , BWG and FCR through 3-6 and 1-6 weeks of age in the group fed the diet containing 0.95% TSAA, comparing with those receiving 0.75% or 0.85% TSAA. Significant (P>0.05) decrease in FI was observed for the group fed the diet containing 0.75% TSAA through 1-6 weeks of age. Addition of copper to the diets of growing Japanese quail at levels 100 and 200 mg/kg diet, significantly improved all traits of growth performance comparatively with those receiving unsupplemented diets during 1-6 weeks of age. The interaction between diets containing 0.95% TSAA and 200 mg Cu Supplementation surpassed all other dietary treatments regard to all performance parameters. However, results showed that, TSAA level and copper supplementation had no significant effects on all carcass traits studied except only the gizzard. Blood contents of TP, Alb, Glb and glucose concentration significantly increased with the level of 0.95 and 0.85% TSAA, while there was no significant increase in A/G ratio among TSAA levels. Plasma protein profile did not show significant differences between the treatment groups at all levels of CuSO₄ supplementation_, while blood glucose had significantly increased with the level of 100 and 200 ppm of Cu. The activity of both AST and ALT significantly decreased at the level of 0.95% TSAA than the other levels, also significant variations between control and other treatments in the ALP activity were recorded. The lowest activity of the previous enzymes was observed at the level of 100 ppm copper sulphate, consequently it can be concluded that the levels of 0.95% TSAA and 200 mg copper sulphate are safe in Japanese quail feeding. It can be concluded that supplementation of Cu at 200 mg/kg and the dietary TSAA at level 0.95 % seemed to be the optimum levels. Chicks fed the diet containing 0.95% TSAA and 200 mg copper /kg diet had almost the best performance value, while the worst performance values were obtained in the group fed 0.75% TSAA without copper supplementation.