Objective:To understanded the pathogen spectrum and epidemiological characteristics of common respiratory viruses in hospitalized patients with severe acute respiratory infection (SARI) in Lanzhou, in order to provide a reference for the prevention, control and treatment of SARI cases in Lanzhou.Methods:From January 2011 to December 2020, 2 571 samples including throat swabs, sputum and a small amount of alveolar lavage fluid from SARI cases in the First Hospital of Lanzhou University, and data and clinical information were collected at the same time, the monitored population was divided into 5 age groups (0 year-, 1 year-, 5 years-, 15 years-, 60 years-), and the nucleic acid detection of common respiratory viruses was performed by multiplex real-time PCR.Results:A total of 9 viruses were detected in 2 571 samples, with a total positive rate of 24.66%. Among them, the top 4 viruses were respiratory syncytial virus (8.71%), rhinovirus (4.60%), influenza virus (4.40%), and parainfluenza virus (3.85%). The 0 year-group had the highest proportion of infants (36.37%), the highest positive detection rate (26.95%), the highest detection rate of respiratory syncytial virus (13.05%) were found in this group, and in the 5 years-group rhinovirus detection rate was the highest (6.13%). The 15 years-group and 60 years- group had the highest detection rates of influenza virus, which were 9.75% and 6.35%. The difference in positive detection rate between different age groups was statistically significant( χ2=12.11, P=0.038). The peak incidence was in winter and spring every year. Conclusions:The virus with the highest infection rate of SARI cases in Lanzhou was respiratory syncytial virus. Different age groups have different dominant viruses. Winter and spring are the epidemic seasons.