The invention relates to the technical field of medicines and in particular relates to application of a 
triterpenoid saponins compound. The invention provides application of the 
triterpenoid saponins compound with a structure formula I to preparation of a 
medicine for treating 
asthma. An experiment testifies that the 
triterpenoid saponins compound with the structure formula I has an obvious inhibition effect on a 
platelet activating factor 
receptor and can be used for alleviating 
tachypnea and accelerated frequency, caused by the 
asthma, and remarkably reducing the amount of Eos (Eosinophile 
granulocyte) in 
rat blood and reducing infiltration on trachea by the Eos; meanwhile, the 
secretion of GM-CSF (
Granulocyte-Macrophage Colony-Stimulating Factor) in BALF (
Bronchoalveolar Lavage Fluid) of guinea pigs can be inhibited and a PAF (
Platelet-Activating Factor) level of 
blood serum of the guinea pigs is remarkably reduced, and the activation of inflammatory cells and the releasing of inflammatory transmitters are stopped, so that 
inflammation of the trachea is alleviated and smooth muscles of 
bronchus are relaxed; the high responsiveness of the trachea is reduced to treat the 
asthma, so that the triterpenoid saponins compound has the effect of treating the asthma and application value.