This paper reports the studying on total flavonoids from stem and leaf of Mosla dianthera Maxim which grow in different circumstance, extracted with different extraction conditions, purified by polycaprolactan and determined. Results showed that the best way is extracted by 75% ethanol in 80℃ for at least 3 hours. The maxim content of the total flavonoids is 867% in No1,1246% in No2 and 316% in No3 respectively.