ObjectiveTo investigate the viral characteristics and epidemic trends of respiratory tract infection (RTI) in children in a hospital.Methods5 384 children who were confirmed RTI in a hospital from January to July 2012 were included in the study, nasopharyngeal secretion of children were performed detection of respiratory syncytial virus（RSV）,influenza virus A/B（FLUA/B）,parainfluenza virus 1—3（PIV1—3）and adenovirus（ADV）.ResultsOf 5 384 children, 1 834 （34.06%）were infected with virus; 1 884 isolates of virus were detected，the major virus was RSV(895 isolates，16.62%)，followed by FLUA (376 isolates，6.98%),FLUB(278 isolates，5.16%),PIV1(179 isolates，3.32%),ADV(138 isolates，2.56%),PIV3(15 isolates，0.28%), and PIV2(3 isolates，0.06%). Constituent ratio of RSV and PIV3 infection were highest in children ＜1 years of age(56.31% and 40.00% respectively), the next were in children of 1-2 years of age(27.04% and 26.67% respectively)；constituent ratio of FLUA was higher in children ＜4 years of age（16.22%-25.53%），FLUB was detected in each age group（7.19%-16.55%）；constituent ratio of PIV1 in children ＜5 years of age was 8.38%-23.46%；constituent ratio of ADV in children of 1-4 years of age was 15.94%-34.78%. Single and mixed infection accounted for 97.55% and 2.45% (45 cases）respectively, infection of PIV1 associated with other virus was the major mixed infection（25 cases），followed by RSV mixed infection （24 cases）and FLUB mixed infection（19 cases）.ConclusionRIT in children in this hospital is mainly caused by RSV, followed by FLUA, FLUB, PIV, and ADV; the positive rate of different virus in different age group is varied.