This study was carried out to evaluate the effects of the addition of different concentrations of licorice extract (LE) in drinking water on the growth performance, carcass characteristic and some blood parameters of Japanese quails aged 2 to 7 weeks. A total number of 90 Japanese quail chicks 14-day old were randomly distributed into three experimental treatments, each one was subdivided into 3 replicates (10 birds / replicate). Birds in the first group provided drinking water without any addition and considered as control, whereas birds in second (T1) and third (T2) treatments were provided with 100 or 450mg LE/liter drinking water, respectively. The results indicated that males received 450 mg LE/liter showed the highest (P<0.05) final body weight and body weight gain followed by those received 100 mg LE/liter compared with the control group. However, the final body weight and body weight gain of female quail did not effected by licorice extract concentrations. In terms of feed intake and feed conversion ratio, males that received 450 mg LE /liter recorded the lowest (P<0.01) feed intake followed by control and treatment 1 (100mg LE/liter) and showed better (P<0.01) feed conversion ratio compared to the other treatments. Also, the feed intake of females showed the same trend of males without significant differences in feed conversion ratio among all treatments. LE concentration had no effect on carcass percentages of both males and females compared to control. The highest of triglycerides and Aspartate Aminotransferase AST were observed in males of control and 450mg LE groups compared to the other treatment. Moreover, female Alanine Transaminase ALT and AST decreased in LE treatments than the controls. However, Tri iodothyronine T3 and Thyroxin T4 hormones increased significantly (P<0.05) in treatment 1 than control and treatment 2. In conclusion, the results of this study indicated that adding licorice extract to drinking water at100mg/L and 450mg/L improved some traits of growing quail's performance at 7 weeks of age.