Objective:To study the effects of electron beam irradiation and 60Co irradiation on the composition changes of four alkaloids in Sophorae Flavescentis Radix, intermediate extracts of Sophorae Flavescentis Radix and Lixieling Tablets. Methods:Sophorae Flavescentis Radix, intermediate extracts of Sophorae Flavescentis Radix and Lixieling Tablets were irradiated at different doses of 0, 1.5, 3, 5, 7, 10, 20, 30, 40 kGy by electron beam irradiation and 60Co irradiation. The contents of oxymatrine, oxysophocarpine, matrine and sophocarpine were determined by HPLC, and the changes of the components before and after irradiation were compared. Results:Oxymatrine, oxysophocarpine, matrine and sophocarpine were among 0.046 9-0.937 4 μg, 0.020 5-0.410 4 μg, 0.098 9-1.977 9 μg, 0.048 7-0.973 1 μg, respectively. The linear relationship was good. The average recovery rates were 98.1%, 100.1%, 100.5%, 96.6%, respectively, and the RSDs were 1.69%, 2.03%, 3.14% and 1.10%, respectively. Electron beam irradiation and 60Co irradiation had no statistical significance on the changes of oxymatrine, oxysophocarpine, matrine and sophocarpine in Sophora flavescens, but had statistical significance in the contents of intermediate extracts of Sophorae Flavescentis Radix and Lixieling Tablets. Conclusion:The established method for the determination of matrine is accurate, reproducible, simple and practical, and can be used for the quality control of Lixieling Tablets. Irradiation has no significant effect on the content of Sophorae Flavescentis Radix, while high dose irradiation has significant effect on the intermediates and finished products of Sophorae Flavescentis Radix, which can provide a basis for quality control and sterilization irradiation of enterprises.