Objectives: To assess the characteristics and forecasting of respiratory viruses epidemic among young children with acute respiratory tract infection (ARTI) in west China. Methods: This study retrospected the epidemic characteristics of respiratory viruses among 11813 pediatric patients with ARTI between March 2018 and March 2020. Results: 11813 samples were collected, with a mean age of 2.25 years. The ratio of the boy: the girl was 1.36. The two predominant viruses were influenza (Flu) A and respiratory syncytial virus (RSV), with Flu A accounting for 47.3% (n=1099), 47.5% (n=1333) and RSV accounting for 32.7% (n=760), 24.7% (n=692) of the positive samples in the two respective years. The positive rate of Flu B was 10.9% and 13.1%, and the other four viruses were <7%. The most common virus was RSV in the <5 years group and Flu A in the 5-10 years group. Flu A and RSV demonstrated pronounced seasonality, and their infection rates increased from October. During the pandemic of SARS-CoV-2, isolation measures led to a decline in the number of ARTI. Conclusions: The study provided surveillance of respiratory viruses in west China. It will provide guidance for medical staff to implement the necessary prevention and management strategies before the outbreak of the virus in the future.