EC50值分别为145.62μg/mL和139.38μg/mL。 Optimization of the extraction technology for total phenol from betel nut seed was carried out. On the basis of one factor tests, the method of response surface analysis with 3 factors including extracting temperature, time and solvent-material ratio on the content of total phenol was adopted. The optimal extracting conditions are as follows: extraction temperature 58℃; extraction time 4h; solvent-material ratio 47mL/g. The predicted value and measured value of total phenol is 148.09mg/g and 146.63mg/g, respectively. The results indicate that the obtained mode developed by response surface methodology is feasible for practical prediction. The experiments of antioxidant activity show that the betel nut seed extract presents the strong antioxidant activities to the DPPH and ABTS radical, and the EC50 is 145.62μg/mL and 139.38μg/mL, respectively.