Abstract： Background::Carbon monoxide (CO) poisoning remains a major cause of accidental injuries and multiple studies have indicated that CO is also associated with significantly severe or long-term toxicity to the central nervous system. Given that CO poisoning causes serious morbidity and mortality, a better understanding of epidemiological features and clinical characteristics of acute CO poisoning in China is crucial.Methods::We collected the clinical data of acute CO poisoning in patients between November 2019 and April 2020 across Shandong province, China and analyzed its characteristics focusing on the weekly amount and the severity of the confirmed cases.Results::A total number of 21,088 acute CO poisoning cases were diagnosed. The overall incidence of acute CO poisoning was approximately 0.021%. On severity rankings, 63% of confirmed cases ( n = 13,378) were mild, 27% (n = 5635) were moderate, and 10% ( n = 2075) were severe. Interestingly, the coastal cities had more confirmed cases than the inland/suburban areas in Shandong. Meanwhile, the number of confirmed cases was negatively correlated with the local mean daily temperature ( P = 0.0167). Conclusions::Mild acute CO poisoning cases accounted for the majority of all confirmed cases during the winter of 2019. In Shandong province, which is located in east China, residents of the coastal cities are more susceptible to CO poisoning than residents of inland cities.