This study aimed to examine and summarize clinical characteristics of Kawasaki disease (KD) at different ages to further strengthen clinicians understanding of children with KD, improving the level of diagnosis, and reducing coronary artery complications of KD. A total of 398 patients with KD who were diagnosed between January 2016 and December 2017 were reviewed retrospectively. These participants were allocated into three groups according to age: group A (<1 year, n=62), group B (≥1 and <5 years, n=286), and group C (≥5 years, n=50). Clinical manifestations, laboratory results, and echocardiographic findings were compared among the groups. Most (71.86%) patients with KD were aged 1-5 years. The prevalence of cervical lymphadenopathy was lowest in group A. The duration of fever before admission was longest in group A. The rate of cervical lymphadenopathy and laboratory data were different among the groups. Group A had higher frequencies of gastrointestinal involvement, neurological symptoms, and redness at the Bacillus Calmette-Guerin inoculation site than the other groups. Infants aged <1 year with KD often have a longer duration of fever before admission, a lower prevalence of cervical lymphadenopathy, and a higher prevalence of gastrointestinal and neurological symptoms.