Abstract: Electrical field stimulation of sensitized guinea pig hilus bronchi induced a long lasting contractile response which was insensitive to atropine, but could be antagonized by a substance P (SP) antagonist. Antigen challenge of sensitized guinea pig main and hilus bronchi evoked a doublephase contractile response w,hich consisted of a rapid contraction and a slow contraction. Both of them were sensitive to SP-antagonist, especially its slow contraction. Disodium cromoglycate (DSCG) inhibited the contractile responses induced by electrical field stimulation and antigen challenge, significantly. These results suggest that DSCG has inhibitory effect on the release of SP sensory nerve fibre endings induced by some stimulators, which might be related to the effect of DSCG against asthma.