This work aims to investigate the effect of traditional Chinese medicine fast-acting asthma relieving mistura (in Chinese, Suxiao Pingchuan Heji) on serum LTC4 expression in mouse models of asthma. 50 KM mice were randomly divided into Group A (control), group B (asthma model), group C (dexamethasone intervention), group D (fast-acting asthma relieving mistura intervention), and group E (intervention by dexamethasone together with fastacting asthma relieving mistura). The asthma models were established by intraperitoneal injection and aerosol inhalation with ovalbumin. The serum LTC4 level in mouse was determined by ELISA method, and the pathological change of lung tissue was observed underlight microscope. There was a little serum LTC4 expression in group A. The LTC4 level in group B was significantly higher than group A (P < 0.01), and that in group C, D, E was significantly lower than group B, respectively (P < 0.01). The inhibition effect on LTC4 expression in group E was obviously greater than group C and D, respectively (P < 0.01), with no significant difference between group C and D (P > 0.05). There was obvious change of inflammatory cell response in group B, with relatively mild inflammatory change in group C, D and E. No inflammatory change was found in group A. Over-expression of LTC4 is closely related to the occurrence and development of asthma. Fast-acting asthma relieving mistura can inhibit the over-expression of LTC4, thus preventing the further development of airway inflammation in asthma.