Objective:To observe the effects of Shugan Hewei Decoction on the expression of Ca,2+,/calmodulin-dependent protein kinaseⅡ(CaMKⅡ)in visceral hypersensitive rats. Methods32 healthy male SD rats were randomly divided into the model group,Shugan Hewei Decoction group,rabeprazole group and blank control group,eight rats in each group. The model of visceral hypersensitivity was established by the chicken ovalbumin combined with esophageal acid perfusion. The expression of CaMKⅡ in spinal cord and the number of positive neurons of rats in each group were observed by immunohistochemistry.  Results:Compared with the blank control group,the expression of CaMKⅡ and the number of positive neurons in the model group were increased significantly (P,<,0.05); compared with the model group, the expression of CaMKⅡ and the number of positive neurons in the Shugan Hewei Decoction group and rabeprazole group were decreased significantly,and the differences were statistically significant(P,<,0.01). The number of positive neurons in the Shugan Hewei Decoction group was less than that in the control group(P,<,0.05). There was no statistically significant difference on the expression of CaMKⅡ between the Shugan Hewei Decoction group and rabeprazole group(P,>,0.05).  Conclusion:Shugan Hewei Decoction could decrease the visceral hypersensitivity by the inhibition of CaMKⅡ expression.