A total number of 60 weaned male New Zealand White rabbits at 6 weeks of age with an average initial body weight 704 ± 20g were randomly divided into four groups, fifteen rabbits /each during the experimental period (May−June 2020). First group was fed the basal diet without any additive as a control group, while 2^nd ,3^rd and 4^th groups were the fed basal diet with hydrolysable tannin as Silvafeed^® ATX (HT, 1.5 g/kg diet), grape seed extract (GE, 0.5 g/kg diet) and a mixture of HT and GE (HT-GE), respectively. The results show that compared with other groups, the HT-GE significantly recorded the best body weight gain and feed conversion ratio compared with control. Whereas, there were no significant treatment effect on carcass characteristics. Indigenous enzyme activity in term of catalase activity was significantly higher both in blood plasma and meat as HT-GE introduced to the diet, meanwhile all supplements form decreased significantly lipid peroxidation as MDA compared to the control group. Plasma total protein, globulin and Immunoglobulin (IgG and IgM) were significantly the highest in the group HT-GE. Plasma cholesterol, triglyceride and liver enzyme functions were decreased without any significant affected between treatments. The economical efficiency ratio also increased with the treatment groups, especially the mixture between HT and GE. Supplementation HT and GE had a beneficial effect as natural anti-oxidant additives by protecting against oxidative stress factors resulting from rearing rabbits through summer months by maintain performance, antioxidative status and immunity functions statuses of the rabbits.