The S protein mediates receptor binding and membrane fusion, and of particular note, it is of great importance to determine host tropism and transmission capacity.5 Zhou et al. demonstrated that the 2019-nCoV use the same cell entry receptor, ACE2, as SARS-CoV.6 The receptor binding region of the 2019-nCoV was more similar to that of SARS-CoV; however, we found that four amino acid substitutions in the receptor binding region of the 2019-nCoV, including S486Q, F485Y, N493G, and Y501V substitutions (2019-nCoV numbering), were different from that of SARS-CoV (Fig. 2), which might affect the receptor binding ability.