Many of the patients have direct or indirect contact with the Wuhan Huanan Seafood Wholesale Market that is belived to be the original place of the outbreak of the 2019-nCoV. However, transmission of 2019-nCoV from fish to human is unlikely. The 2019-nCoV and fish CoVs such as Beluga Whale CoV/SW1 belong to different genera and apparently have different host ranges. As the Wuhan seafood market also sells other animals, the natural host of 2019-nCoV awaits to be identified. Due to the possibility of transmission from animal to human, CoVs in livestock and other animals including bats and wild animals sold in the market should be constantly monitored. In addition, more and more evidence indicate the new virus 2019-nCoV is spread via the route of human-to-human transmission because there are infections of people who did not visit Wuhan but had closed contact with family members who visited Wuhan and got infected.