This study was aimed at understanding the pollution distribution pattern of avian influenza virus in the environment in poultry related places in Shandong Province, to provide a scientific basis for the prevention, control,
prediction, and early warning regarding human infection with avian influenza. From 2020 to 2023, 6523 environmental samples were collected in 16 cities in Shandong Province from four types of poultry-related places. Fluorescence quantitative PCR was used for nucleic acid testing of influenza A virus. Positive samples were furth er identified for the H5, H7, and H9 subtypes of avian influenza virus. The epidemiological characteristics of avian influenza viruses in the poultry related environment of Shandong Province were described, and inter-rate comparisons were performed with the χ2 test. During 2020–
2023, 6523 environmental samples were collected, and 1007 cases positive for avian influenza virus were detected, with a positivity rate of 15.44%. H5, H7, and H9 subtypes and mixed infections were detected. H9 was the main subtype (88.48%) in positive specimens. A significant difference in positivity rates was observed among regions (χ2= 431.956，P＜0.001), and the highest positivity rate was 28.93%. Significant differences in positivity rates were observed among monitoring sites (χ2=304.604, P＜0.001), sample types (χ2=109.678, P＜0.001), and quarters (χ2= 64.963, P＜0.001). The positive detection rate was highest at monitoring sites in urban and rural live poultry markets (20.12%), and the positive detection rate of samples collected by wiping meat cutting board surfaces was higher than that of other samples (22.56%). The peak positive detection rate occurred in spring (20.31%). Widespread contamination with avian influenza virus was observed in poultry environments in Shandong Province. The H9 subtype, the main pathogen, coexisted with H5 and H7 subtypes, thus posing a risk of human infection with avian influenza. Therefore, prevention and control of avian influenza must be strengthened in key seasons, areas, places, and links.