Objective To observe the anti-enterovirus 71（ EV71） effect of Ganlu Xiaodu Micropills and its disassembled formulas in vitro. Methods The cell culture technology was used and the virulence of virus was measured. The Reed-Muench method was used to calculate 50% tissue culture infective dose（ TCID50） and 100 TCID50was determined for the experiment. The drug solutions of Ganlu Xiaodu Micropills（ whole formual）

heatclearing toxin-resolving formula（ heat-clearing and toxin-resolving medicinal ingredients of Ganlu Xiaodu Micropills）

turbidity-transforming dampness-disinhibiting formula（ turbidity-transforming and dampness-disinhibiting medicinal ingredients of Ganlu Xiaodu Micropills） and Ribavirin were diluted with maintenance medium at a ratio of 1 ∶ 8

1 ∶ 16

1 ∶ 32

1 ∶ 64

1 ∶ 96

1 ∶ 128 and 1 ∶ 256

respectively. The optical density（ OD） value was measured by MTT assay and the cell viability was calculated according to the OD values of drugs at different concentrations. The linear regression curve was drawn with drug concentration as the horizontal axis（ g / ml） and cell viability（ %） as the vertical axis. A concentration of 90% cell viability was selected as the pharmacodynamic experimental concentration. The drug solutions of Ganlu Xiaodu Micropills

heat-clearing toxin-resolving formula

turbidity-transforming dampnessdisinhibiting formula and Ribavirin at a concentration of 90% cell viability were mixed with 50μl 100TCID50virus and added to the monolayer human malignant embryonic rhabdomyosarcoma cells（ RD cells）. Four duplicate wells were established and equipped with normal cell control and virus control. The viral suppression rates of drugs were calculated by MTT assay. Results The TCID50was 10- 2. 89/ ml. The concentration of 90% cell viability was 10- 2. 43= 0. 0037 g /ml

10- 2. 7= 0. 0020 g / ml

10- 2. 09= 0. 0081 g / ml

and 10- 3. 19= 0. 64 mg / ml in Ganlu Xiaodu Micropills

heat-clearing toxin-resolving formula

turbidity-transforming dampness-disinhibiting formula

and Ribavirin

respectively. The viral suppression rate of heat-clearing toxin-resolving formula

Ganlu Xiaodu Micropills

turbiditytransforming dampness-disinhibiting formula

and Ribavirin was 97. 4%

91. 74%

75. 64%

and 36. 99%

respectively. Conclusion The anti-EV71 effects of Ganlu Xiaodu Micropills and its disassembled formulas are superior to that of Ribavirin

and heat-clearing toxin-resolving medicinal plays a stronger role.