Objective：To investigate the relationship between infection and pediatric acute urticaria and to analyze the clinical charac－teristics of pediatric acute urticaria caused by infection. Methods：Clinical data of 149 patients with acute urticaria were collected from January 2009 to March 20l2 and were analyzed retrospectively. Results：（1）Among 149 cases of pediatric acute urticaria，127 cases（85.2%） was caused by infection，especially respiratory tract infection. Numbers of white blood cell，neutrophile granulocyte and C-reactive protein were increased indicating the bacteria infection. （2）In virus detection，positive rate of coxsackie virus was 24.5%，obviously higher than that of other common viruses. （3）Features of skin lesion：the lesion lasted for 0.5-1.0 d and tended to spread to the whole body；annular or geographic papules and plaques were seen in most patients and a few patients might develop into hemor－rhagic lesions；meanwhile，some lesions faded to leave geographic border or brownish pigmentation；besides，53.5% cases were accom－panied with angioedema；skin manifestations might come with the severity of infection；the duration was about 7.0-11.0 d. （4）64.4% cases were accompanied with digestive symptoms and 43.5% cases were accompanied with increased of creatine kinase-MB；（5）An－ti-allergic agents as well as anti-infective drugs had positive effect. Conclusions：（1）Infection is the main cause of pediatric acute urticaria and the bacteria may dominate the infection. （2）In virus infection，coxsackie virus is the most common. （3）There are some special features in skin lesion of pediatric acute urticaria caused by infection. （4）In fact，quite a few patients are accompanied with di－gestive symptoms and some of which may get myocardial injury. （5）We should attach importance to enough course of anti-infection treatment.