The aim of this study was to investigate the effect of in ovo feeding of different level of vitamin B complex (Bcx) on broilers production performance, carcass characteristic, blood biochemical and antioxidant status .During day 14 of incubation, 240 Cobb 500 eggs were purchased and evenly split among six groups according on the in ovo treatment. The control group was T1. In the meanwhile, groups T2, T3, T4, and T5 were given in ovo injections with 0.5 mL of distilled water and 100, 200, or 300 mg of vitamin Bcx per egg, respectively. The experimental groups did not differ in terms of chick weight upon hatching. In the meanwhile, there was no difference in feed consumption between the T3 and T5 groups and the control group in terms of final body weight and body weight increase from 1 to 5 weeks of age. The feed conversion ratio for animals aged 1 to 5 weeks did not vary significantly across groups. The relative weight of the bursa rose considerably in the T4 and T5 groups, but the relative weight of the spleen increased significantly in the T4 group compared to the control. As compared to the control group, in ovo vitamin Bcx treatment at 300 ng/egg significantly boosted serum albumin as well as muscle SOD and TAC activity. The current study found that in ovo injection of vitamin Bcx at a dose of 300 g/egg had positive effects on the relative weight of lymphoid organs and the antioxidant activity of muscles. Thus, more research is required to assess the effects of various in ovo vitamin B-group combinations on broiler performance for commercial adaption.