Objective:to observe the influence of hyoscyamine(654-2)on the adverse reaction of Azithromycin in treating the patients with pneumonia.Methods:212 pneumonia patients in our hospital were divided randomly into two groups:Azithromycin group (106 cases)and group of Azithromycin combined with 654-2 injection(106 cases).Then the therapeutic effects of the two groups were observed carefully.Results:The adverse reaction of Azithromycin in the group of Azithromycin combined with 654-2 injection were obviously lower than that in the Azithromycin group(P0.05);besides,the therapeutic effect of the former was much better than the latter (P0.05).Conclusion:Azithromycin combined with 654-2 injection could not only lessen the adverse reaction of Azithromycin but also raise the therapeutic effect in treating patients with pneumonia.