Responses to ACh, pilocarpine, BaCl₂ and KCl in isolated duodenum from SART stressed mice (specific stress caused by alternating rhythm in temperature) were investigated using the Magnus's method, and the results were compared with those seen in non-stressed mice. We found that the ACh response was significantly decreased, while the BaCl₂ response was not decreased in SART stressed mice duodenum, as compared with the non-stressed controls. And it is recognized that pretreatment with adrenergic and anticholinergic drugs inhibited the decrease of ACh response. These results suggest that SART stressed mice may be unbalanced in the autonomic nervous system.