Abstract： Objective To verify the hypothesis that Acetaminophen exposure may increase the incidence of asthmatic diseases in children. Methods A total of 3189 children with fever hospitalized in our hospital between August 2014 and December 2015 were included as the subjects in the study,and divided into the study group and the control group according to a randomized and double?blind trial. The study group and the control group were divided into high?dose group and low?dose group. The study group and the control group receivedAcetaminophen suspension andIbuprofen suspension for fever control,respectively. The rates of outpatient visit and hospitalization for asthmatic diseaseswithin three months after the treatment were compared between the study group and the control group. Results Comparing the rate of outpatient visit with the control group,the relative risk inthe study group was 1.65 (95% confidence interval:1.40?1.95). Comparing the rate of hospitalization with the control group,the relative risk in the study group was 2.32 (95% confidence interval:1.25~4.32). Conclusion This studyverifies that Acetaminophen exposure may increase the incidence of asthmatic diseases in childrencompared with Ibuprofen.The adverse effects of using Acetaminophen should be paid attention when choosing antipyretic drugs in clinical practice.