Objective To observe the virostatic action of Tuire Jieduling Decoction（Decoction for effective defervescence and detoxification） on the H1N1 Type A influenza virus.Methods In vitro experiment:the MDCK cell suspension 105/ml was vaccinated onto the 96-hole plate

using the cell maintenance liquid to dilute continuously twice as much the Tuire Jieduling Decoction to 5000

2500

1250

625

312.5

156.25

78

39

and 19.5mg/L in concentration in series

and dilute twice as much the virazole injection to 125

62.5

31.3

15.6

7.8

3.9

2.0

1.0

and 0.5mg/L in concentration in series.The lesion effect of cells was observed and the virostatic rate was calculated.In vivo experiment:eighty BALB/c mice were randomized into control group

model group

Tamiflu group

and Tuire Jieduling group

with 20 in each.Except for the control group

mice of the other groups were vaccinated nasally with the H1N1 Type A influenza virus 50μl

a dose ten times of the half lethal dose（LD50）.The medication was given since the day of viral vaccination.Tuire Jieduling group was administered Tuire Jieduling Decoction 4133g/kg each day and the Tamiflu group was applied Tamiflu 20mg/kg each day through intragastric feeding.Ten mice of each group were observed on the survival rate

five were executed on the 4th day

and the other five on the 8th day after the first medication to measure the lung wet weight and intrapulmonary virus TCID50.Results In vitro experiment:the inhibiting rate of the 5000

2500

1250

625

and 312.5mg/L Tuire Jieduling Decoction subgroups and the 125

62.5

31.3

15.6mg/L virazole subgroups was all over 50%.In vivo experiment:the survival rate of the model group was 0

and that of the Tamiflu group and Tuire Jieduling Decoction group was 90% and 60% respectively.On the 4th day and 8th day after viral infection

the lung wet weight and intrapulmonary virus TCID50 of the Tamiflu group and Tuire Jieduling Decoction group were all significantly dropped in comparing with the control group

and the difference was statistically significant（P<0.05 or P<0.01）.Conclusion Tuire Jieduling Decoction is virostatic on the H1N1 Type A influenza virus both in vivo and in vitro.