A total number of 144 Japanese quail birds (96females and 48males) at 12 weeks old were used to evaluate the physiological value of taurine supplementation to plant protein diet on laying quail performance. Quails were weighed individually, randomly distributed into four experimental groups; each group contained 36 birds (24 hens and 12 males). Two different basal diets were formulated; the first one containing fish meal (animal protein diet, AP) and fed to the first treatment (T1), another one was containing corn-soybean (vegetarian protein diet, VP) and fed to the second treatment group(T2). The third and fourth treatment groups (T3 and T4) were fed the second diet (VP) with taurine addition 0.15 and 0.30 % (VP0.15 and VP0.30, respectively). The results indicated that hens fed taurine supplementation (T3 and T4) to the VP numerically improved egg laying rate, egg number and egg mass while, egg weight was numerically decreased. Heterophils (H) and H/L ratio were significantly (P≤0.05) increased for the hens fed T3 as compared with those fed T1 and T2. Antibody titter against avian Newcastle disease at 14 days post-vaccination was significantly (P≤0.01) increased for the hens fed T1and T4 as compared with those fed T2 and T3 diets, while at 21 days post-vaccination it was significantly (P≤0.01) decreased for the hens fed T2 as compared with those fed T1 and T4. Serum lipid profile was improved in T3 and T4 in comparison with T1. Lipid peroxide concentration was significantly decreased, total antioxidant capacity was significantly (P≤0.001) increased in VP diets in comparison with AP diet and the improvements were pronounced with including taurine in VP diet. In conclusion, taurine supplementation for laying Japanese quail fed vegetarian protein could improve immune response, antioxidative properties and decreased blood lipids profiles.