Abstract: In order to revolve physiological mechanism of drought tolerance in sweetpotato, Jishu21 (JS21) with strong drought tolerance and Jizishu1(JZS1) with weak drought tolerance were choosed to research antioxidative character of sweetpotato under normal and drought treatments in rain-shelter. The results showed the decreasing range of H2O2 content and O2— generation rate in fibrous root, thick root, storage root of JS21 was more larger than JZS1. Whether normal or drought treatment, H2O2 content and O2— generation rate were the lowest in fibrous root, H2O2 content was the highest instorage root, and O2— generation rate was the highest in thich root. Under drought condition, the increasing range of Vc and polyphenol content in two varieties were about the same, but the decreasing range of Vc and polyphenol content in three root types of JS21 was more larger than JZS1. Whether normal or drought treatment, Vc and polyphenol content were the highest in thick root, and the lowest in storage root. The activities of SOD, CAT, APX and PPO were the highest in fibrous root of two varieties, but CAT, APX and PPO were the lowest in storage, and SOD were the lowest in thick root. Under normal treatment, the activity of POD was the highest in thick root, but lowest in storage root. Under drought treatment, the activity of POD was the highest in fibrous root, but lowest in thick root, and the increasing range of SOD, CAT, POD, APX and PPO in three root types of JS21 were more lager than JZS1 from transplanting to 3rd sampling date, the decreasing range of CAT, POD, APX and PPO in three root types of JS21 were more smaller than JZS1 from 3rd sampling date to 5th sampling date. In conclusion, 70 days after transplanting maybe was the time of the highest antioxidative capacity, antioxidant content was higher in thick root, but antioxidantive enzymes were higher in fibrous root, antioxidative enzymes of the variety with stronger drought tolerance increased more faster and decreased more slower under drought condition.