In the present paper,the authors aimed to detect the binding of monoclonal antibody and polyclonal antibodies in sera of patients with recombinant house dust mite allergen (rDer p2) by surface plasmon resonance (SPR) technique.This technique is superior to other methods,like enzyme-linked immunosorbent assays (ELISAs) in studying the interaction between biomolecules because no labeling and sample separation are needed.The allergen rDer p2 was immobilized on carboxymethyldextran-modified sensor chip surface by amine coupling.Surface plasmon resonance measurements of monoclonal antibody and polyclonal antibodies in patients’ sera revealed that their bindings diverge widely;the binding of patients’ sera was remarkably lower than that of monoclonal antibody.At the same time,the binding of patients’ sera with rDer p2 varied among patients allergic to dust mite.This study could provide an easy,fast and real-time way for clinical allergic diseases diagnosis.