The application describes neutralizing chimeric and humanized anti-human IL-9 antibodies, and the use thereof to identify neutralizing epitopes on human IL-9 and as medicaments to prevent and treat asthma, bronchial hyperresponsiveness, atopic allergy, and other related disorders. Particularly disclosed are recombinant antibodies derived from three murine anti-human IL-9 antibodies identified infra as MH9A3, MH9D1, and MH9L1.