Objective To investigate the clinical characteristics and changing trends of febrile seizures (FS) in children. Methods The clinical data of 1 922 children with FS admitted from 2004 to 2013 were analyzed retrospectively. The clinical characteristics and changing trends of FS in the two five-year periods were analyzed. Results In 1 922 children with FS, the male/female ratio was 2.27:1. The mean age at onset was 3.0±1.8 years, while the peak age at onset was 1-3 years. There were 1 556 children (80.96%) with simple FS and 366 (19.04%) with complex FS. The number of children with FS in the second five-year period (1 202 cases) increased by 66.9% compared with that in the first five-year period (720 cases). The proportion of children with complex FS was significantly higher in the second five-year period than in the first five-year period (21.13% vs 15.56%; P<0.05). In children with simple FS, there were no significant differences in the age and body temperature at onset, convulsion duration, and the incidence of complications between the two five-year periods (P>0.05). However, children with complex FS had a significantly lower age at onset, a significantly lower body temperature at onset, a significantly longer convulsion duration, and a significantly higher incidence of complications including myocardial injury and hyponatremia in the second five-year period than in the first five-year period (P<0.05). Conclusions In the last decade, the number of children with FS and incidence of complex FS increased, and the outcome became worse according to clinical characteristics, suggesting that more attention should be paid to timely diagnosis and treatment of complex FS.