Abstract: To study the inhibitory action of anthocyanins from purple sweet potato (APSP) to TGEV in vitro, the sample of anthocyanins extract was purified and its structure was identified by HPLC-MS. The prepared anthocyanins extract was acting on disseminated TGEV in swine testicle cell, then research its influence on the morphological changes as well as apoptosis of ST cell and reveal its prevention and treatment on TGEV. The result showed that the extract of purple sweet potato contains eight major anthocyanins. When mass concentration of APSP was less than 60μg/mL, ST cell grow well without the cell toxicity. Introduced TGEV to ST, 20μg/mL APSP could restrain the proliferation of TGEV after 48h and 72h cultivation, and inhibition effect was dose-response in the security concentration range. At the same time, it was obvious that there was better prevention effect than treatment effect in this study. In summary, APSP had very good antiviral efficacy for TGEV in 20～60μg/mL.