OBJECTIVES:  This study is to analyse age, disease category, time of emergency treatment and regularity of visiting doctors in order to realize the distribution of disease spectrum and epidemiological analysis in emergency department in the top three hospital in China. METHODS: To select 29,654 cases in emergency department of hospital database of 2013. The top five emergency diseases were studied by retrospective research. Data analysis was performed with STATA software package. ncy department in the top three hospital in China. RESULTS: The majority of the emergency cases were young people under 40 years old. Male patients (53.9%) were more than female patients. The frequency of emergency visit is 2.7 average per year, male patients get 3.0 visits more than female 2.4 visits. About 33.9% of  patients at one's own expense. Diseases in the top five were respiratory disease, trauma, digestive system diseases, circulation system disease, urinary diseases, respectively. Respiratory disease was the leading member in the spectrum, accounting for 25.5%. Poisoning patients account for 1.6% of all emergency cases. Wounded patients mostly centralized from May to August, and the bottom periods of the treatment time appeared in midnight (0:00 – 6:00), accounting for 5.5%. CONCLUSIONS: Composition of emergency disease spectrum and characteristics of time distribution can help to develop new prevention and treatment strategies for improving quality and increase efficiency. The treatment for respiratory disease headed the list of emergency disease spectrum need to optimize medical resourse utilization and process improvement.