〔Abstract〕 Objective To understand the molecular epidemiological characteristics ofNorovirusoutbreaks and the genome evolution ofNorovirusepidemic strains in Hainan Province from 2020 to 2022. Methods The information and samples have been collected from thenorovirusoutbreaks from 2020 to 2022.Noroviruswas detected by using the real-time PCR in these samples, then the detected sequences were amplified the analyzed. TheNorovirussequences of 8 strains had been amplified and analyzed. Results From 2020 to 2022, 39 gastroenteritis outbreaks were reported, and 25 outbreaks caused byNoroviruswhich mainly occurred in childcare institutions and schools(20/25,80%). TheNorovirusoutbreaks were mainly concentrated in counties around Haikou(northeast), which including Ding′an(5 cases), Wenchang(4 cases), Chengmai(4 cases), and Lingao(3 cases); following by western regions which included Baisha(2 cases), Ledong(2 cases), and Dongfang(3 cases). 1 case was in Wanning in the southeast. Among individuals aged 2-17, the positive proportion ofNorovirusin males was higher than that in females. Among individuals aged over 55, the proportion ofNoroviruspositive in females was higher than that in males. The gender of positive samples among individuals aged 18-40 was related to their profession. According to RT-PCR typing and sequencing, GII groupNoroviruswere classified in13 outbreaks. There were 4 genotypes detected. GII.2 [P16] was the main epidemic strain with 60%(9/13), and the other three genotypes were GII.4 Sydney [P31](15.4%, 2/13) GII.4 Sydney [P16](7.7%, 1/13) and GII.3 [P12](7.7%, 1/13). Further genic analysis of 8Norovirusstrains showed that all of them were still in the same branch as the previous strain, and all exhibited a certain amount of amino acid variation. Conclusion Norovirusis the main pathogen of gastroenteritis outbreaks in Hainan province, and the main epidemic strain is GII.2 [P16]. It is necessary to continue to strengthen the monitoring that provides scientific evidence for the prevention and control ofnorovirusoutbreaks in Hainan region.