Abstract: The study aims to evaluate the effects of different doses of ⁶⁰Co-γ rays and Fe⁺ on the biological characteristics and Phytophthora infestans (Mont) of tomatoes.‘Beautiful pink 15’and Bolrorpagokue were used as materials, whose seeds were irradiated by 40 Gy, 60 Gy, 80 Gy, 100 Gy doses of 60Co- γ rays and 4Mev9×1012 doses of Fe⁺, and germination rate, growth characteristics, fruit characteristics and Phytophthora infestans (Mont) were determined. The results showed that after being irradiated by 60 Gy and 100 Gy doses of 60Co- γ rays, the germination rate of‘Beautiful pink 15’and Bolrorpagokue were greater than that of the contrast. After irradiation by 4Mev9 × 1012 doses of Fe⁺ , the plant height of‘Beautiful pink 15’and Bolrorpagokue were greater than that of the contrast. Except 4Mev9×1012 doses of Fe+ irradiation, the leaf index of‘Beautiful pink 15’was lower than that of the contrast, the leaf index of Bolrorpagokue was greater than that of the contrast. The stem diameter of‘Beautiful pink 15’irradiated was more than that of the contrast except 4Mev9×1012 doses of Fe⁺ irradiation, and the stem diameter of Bolrorpagokue irradiated was more than that of the contrast except 60 Gy and 80 Gy doses of ⁶⁰Co-γ rays irradiation. The fruiting rate of‘Beautiful pink 15’ decreased and the fruiting rate of Bolrorpagokue increased. After irradiation by different doses of ⁶⁰Co-γ rays and 4Mev9×1012 doses of Fe⁺, the fruit shape index of‘Beautiful pink 15’was more than that of the contrast, and the fruit shape index of Bolrorpagokue was lower than that of the contrast. With 4Mev9×1012 doses of Fe⁺ irradiation, Phytophthora infestans (Mont) of‘Beautiful pink 15’was superior to that of the contrast. Phytophthora infestans (Mont) of 4Mev9 × 1012 doses of Fe⁺ irradiation and 100 Gy doses of 60Co- γ rays irradiation of Bolrorpagokue were superior to that of the contrast.