Objective:To optimize extraction technology of total flavonoids from Lysimachia paridiformis

and investigate its in vitro antopxidation. Method: With yield of total flavonoids as index

single factor and orthogonal test were used to optimized extraction technology of total flavonoids from L. paridiformis with solid-liquid ratio

the concentration of ethanol

reflux time and temperature as factors;Scavenging action and reducing power of total flavonoids on hydroxyl radical and superoxide anion free radical were determined by UV spectrophotometry. Result: Optimum extraction technology of total flavonoids from L. paridiformis was:ethanol concentration 65%

ratio of solid-liquid 1:25

reflux temperature 65℃

extraction time 4 h

yield of total flavonoids of 1.69%;Total flavonoids from L. paridiformis had good reducing power and ability to inhibit free radical

and reducing power and scavenging hydroxyl radical activity increased with increasing the concentration of total flavonoids. Conclusion: total flavonoids from L. paridiformis had significant antopxidation.