Abstract:Objective: To research into the cause of distinction in antiendotoxic activation of Radix Isatidis from different cultivated populations. Method: 19 samples of Radix Isatidis were gathered.12 portions of seeds were cultivated in the same field in Shanghai,and the selected and artificially bred autotetraploid seeds were planted in 5 different locations.All the samples were compared through antiendotoxic experiment.HZResults: There are some marked distinction among the 19 samples from different populations.The distinction of the 12 samples cultivated in the same field didn‘t disappear.The activation of autotetraploid from 5 different locations didn‘t vary on the whole. Conclusion: Germplasm is the main factor to cause activation distinctions of Radix Isatidis,while environment is less important.