Objective To evaluate influence of Azithromycin on breath hydrogen test(BHT) in acute upper respiratory infection(AURI) in Children.Methods Fasting BHT and lacunose BHT were respectively performed by using HD-1 breath hydrogen detector for 38 inpatients before and after receiving Azithromycin.Fasting BHT of 115 healthy controls were determined.Results After Azithromycin was given,Fasting BHT was lower than that before Azithromycin used(P