Abstract: To reveal the relationship between total phenols（TP）of Saxifraga stolonifera and inhibition of the activity of phospholipase A₂（PIR）in Deinagkistrodon acutus venom,we used the single factor and Box-Behnken methods to optimize the extraction conditions of TP of Saxifraga stolonifera and PIR. The effect of various experimental factors on the yield of TP and PIR in the extraction of S. stolonifera by ultrasonic assisted extraction were investigated respectively,and the correlation between the content of TP and PIR were analyzed.The results showed that when the particle size was 60 mesh,the material to liquid ratio was 1∶50,the ultrasonic power was 250 W,and the ultrasonic time was 1.8 h,the content of TP in the aqueous extract of S. stolonifera and its inhibitory rate（PIR）of the PLA₂ activity in D. acutus venom could reach the optimal ultrasonic-assisted extraction process conditions. The content of TP was（86.90±0.46）mg·g^-1,and the PIR was（40.91±0.21）%.The results of correlation analysis showed that the content of TP and the PIR were extremely significant correlation（P＜0.01）,indicating that the TP might be the material basis of S. stolonifera to inhibit the PLA₂ activity in D. acutus venom.