Abstract: Disclosed are an antibody (preferably a fully human antibody R66) against respiratory syncytical virus RSV, encoding nucleic acids thereof, a vetor and a host cell comprising the same, and a preparation method thereof. Disclosed are also a use of the antibody (preferably a fully human antibody R66) against RSV in the prevention and treatment of RSV-related diseases, and a use of the same in detecting TSV. The above antibody against RSV is preferably a fully human monoclonal antibody. Compared with other animal-derived (e.g., murine) anti-RSV antidodies, the immunogenicity caused by species differences is greatly reduced. With good specificity and affinity, if used for clinic, it will greatly reduce side effects.