研究了稀水溶液中过氧化氢酶的辐射失活,给出了过氧化氢酶生物活性与吸收剂量的关系以及辐射气氛、温度和溶液中酶的初始浓度对酶活性的影响。结果表明,低温、较高的酶初始浓度和体系中的氧对过氧比氢酶的辐射失活有不同程度的抑制作用。发现添加剂CH_3CH_2OH、HCOONa和EDTA对稀水溶液中过氧化氢酶的辐射失活有明显的保护作用。同时讨论了失活机理和添加剂保护机理。 The radiation inactivation of catalase in dilute aqueous solution was studied. The relationship between the biological activity of catalase and the absorbed dose and the effect of radiation atmosphere, temperature and the initial concentration of the enzyme in solution on the enzyme activity were also studied. The results showed that low temperature, high initial concentration of enzyme and oxygen in the system had different degrees of inhibition on the radiation inactivation of peroxy-hydrogenase. It was found that the additive CH_3CH_2OH, HCOONa and EDTA had a significant protective effect on the radiation inactivation of catalase in dilute aqueous solution. The deactivation mechanism and additive protection mechanism are also discussed.