The project was carried out to study the contamination levels of Norovirus in oysters in Beijing city.Methods The Norovirus was extracted from digestive glands by phosphate buffer containing proteinase K. The RNA was extracted and purified with virus RNA extraction kit. Norovirus RNA was detected using Taqman-based one-step real time reverse transcription-polymerase chain reaction (real time RT-PCR) and quantitative analysis was performed. ResultsThree hundred and fifty-six oyster samples were detected. Fifty-seven samples were positive, including twelve GGI positive samples alone, thirty-nine GGII positive samples alone and six samples of GGI and GGII positive both. The range of the quantity of Norovirus in positive samples was 3.7×10³-2.8×10⁵ gene copies/g(digestive gland).Conclusion The oysters sold in Beijing were contaminated by Norovirus. The monitoring of Norovirus in oysters should be strengthened and risk assessment of Norovirus should be carried out to ensure safety and health of consumers and reduce the burden of disease caused by norovirus that causes diarrhea.