Objective: To analyze the etiological and clinical characteristics of oral emergency patients under 18 years with dental trauma, and to provide guidance on the prevention and treatment in children and adolescents. Methods: A retrospective study on the intact data of the dental trauma patients under 18 years from January 2016 to December 2018 in the Department of Oral Emergency in Peking University School of Stomatology was conducted, and the distribution of the patients’ gender, age and visiting time, as well as the number and position of traumatic teeth, diagnostic classification, and multiple injury with dental trauma were analyzed. Results: During the period, 54.2% of the first visit dental trauma patients (10 164) were children or adolescents (5 506). The two peak ages were 3-4 and 7-9 years. The incidence of the male was higher than the female in every age group (Wilcoxon test, P<0.001). From May to June and September to November, there were more cases of dental trauma. The peak time of daily dental trauma cases was from 19:00 to 20:00 (Jonckheere-Terpstra test, P<0.001). The positions of traumatic teeth in both sides were approximate symmetrical, and maxillary central incisors were the most affected. 52.3% of the patients suffered multiple teeth injuries. Among the permanent teeth trauma, enamel and dentin fracture was the most common (24.7%), followed by concussion (20.5%), sub-luxation (17.9%) and complicated crown fracture (14.4%). And among the primary teeth trauma, subluxation was the most common (31.1%), followed by concussion (14.5%) and lateral luxation (9.5%). 19.7% of the children and adolescent dental trauma patients were also suffered maxillofacial soft or hard tissue injury. Conclusion: The incidence of dental trauma in children and adolescents is higher than that in adults. There were two age peaks among the children and adolescents patients. Primary teeth and young permanent teeth were usually suffered. Clinical treatment should be considered along with the characteristics of child tooth growth. In order to prevent the occurrence of dental trauma, early orthodontic intervention should be carried out in children with severe overjet. Families, schools and nursery institutions should strengthen the protection against dental trauma.