OBJECTIVE： To study the effects of 60Co-γ radiation on the botanical traits and property of Andrographis paniculata， and to screen suitable irradiation dose. METHODS： The seeds of A. paniculata were irradiated by 60Co-γ rays with different irradiation doses（0，10，20，50，100，200，300 Gy）. The botanical traits indexes of A. paniculata as seed germination rate， root length， seedling rate， seedling height， leaf area， fresh weight， dry weight， stomata number of lower epidermis of leaf， and its property indexes as the contents of andrographolide， dehydrated andrographolide and chlorophyll， activity of T-SOD enzyme and CuZn-SOD enzyme， were determined after radiation. The coefficient of variation （CV） was calculated. The linear regression analysis was performed for seedling rate， and medial lethal dose was calculated. The correlation analysis was performed between the parameters of botanical trait and quality property with irradiation dose. Cluster analysis was conducted for M1 generation of A. paniculata in different irradiation dose groups by connection method combined with squared euclidean distance. RESULTS： Different irradiation doses showed different effects on botanical traits and property of A. paniculata. According to the average value of CV， the index of botanical traits was ranked as leaf area ＞ fresh weight ＞ dry weight ＞ plant height ＞ root length ＞ stomata number ＞ seedling rate ＞ germination rate； among different irradiation dose groups， the coefficient of variation was ranked as 50 Gy＞200 Gy＞100 Gy＞20 Gy＞10 Gy＞300 Gy＞0 Gy. According to the average value of CV， the index of property was ranked as dehydrated andrographolide content＞andrographolide content＞chlorophyll content＞CuZn-SOD enzyme activity＞T-SOD enzyme activity； among different irradiation dose groups， the coefficient of variation was ranked as 100 Gy＞50 Gy＞200 Gy＞20 Gy＞10 Gy＞300 Gy＞0 Gy. The medial lethal dose was 195.10 Gy. According to the botanical traits， M1 generation of A. paniculata of 7 dose groups could be divided into 4 types. According to the property， M1 generation of A. paniculata of 7 dose groups could be divided into 3 types. CONCLUSIONS： The suitable irradiation dose interval for irradiating A. paniculata is 50-200 Gy.