X-irradiation is a kind of immunosupression which dangerous for health. X-ray can disturb limfositâ€™s capability to cleavage then reduce the infection immune response. Decreasing immune response, caused by X-irradiation, can be shown in the decrease of antibodies production. The aims of this research were to know significant differenceâ€™s antibodies production among the doses of 0.0 Gy, 0.5 Gy, 1.5 Gy, and 3.0 Gy X-ray and the effect of X-irradiation on the BALB/c mice antibodies production after tetanus toxoid immunization. Mice were grouped into four groups with the treatments of 0.0 Gy dose, 0.5 Gy dose, 1.5 Gy dose, 3.0 Gy dose X-ray for 1st, 2nd, 3rd, and 4th group respectively. External irradiation was applied once on the whole body of mice. Tetanus toxoid immunization was done 24 hours after Xirradiation. Indirect ELISA was used to determine the presence of antibodies in serum samples as the quantitative data. Its were analyzed by one way ANOVA and regression. One way of ANOVA was done to know significant differenceâ€™s antibodies production among the doses of 0.0 Gy, 0.5 Gy, 1.5 Gy, and 3.0 Gy X-ray then continued with DMRT on 5% significant rate if there was any marked difference. Regression was done to know the effect of X-irradiation on the BALB/c mice antibodies production after tetanus toxoid immunization. Qualitative observations were done on poisoned symptom, the changes of physical and behavior, and mortality. The result of the research showed that there werenâ€™t significant differenceâ€™s antibodies production with tetanus toxoid vaccine gift among the dose of 0.0 Gy, 0.5 Gy and 1.5 Gy as the same as 0.5 Gy, 1,5 Gy, and 3,0 Gy dose of X-ray. There was a significant difference at 3.0 Gy and 0.0 Gy dose of X-ray. X-irradiation influenced the antibodies production with tetanus toxoid vaccine gift by caused antibody rate degradation along with the increasing of X-ray dose.