Objective: To investigate the effects of Belamcanda chinensis extract on the contraction of isolated guinea-pig tracheal smooth muscle by serum pharmacological method. Method: The guinea-pig tracheal smooth muscle was isolated in the Kreb’s solution

and its contraction was induced by histamine (His). The inhibitory effects of serum-containing drug on contraction of isolated tracheal strips were observed

and the constriction rate was calculated in 3

5

10 minute. Result: The serum-containing drug could significantly inhibit the contraction of the guinea-pig tracheal smooth muscle induced by His

in the dose 0.46 g·kg-1 group in 3

5

10 min antispasmodic rate was 44.29%

45.27%

48.30%; high dose (0.92 g·kg-1) in 3

5 min antispasmodic rate was 31.17% and 31.83%

compared with the control group there was a significant difference (P<0.05 or P<0.01)

and the effects were better in 5 minute. Conclusion: The B.Chinensis extract has inhibitory effect on contraction of tracheal smooth muscle induced by His.