In this paper we report attempts to directly detect the different binding property between monoclonal hepatitis B virus surface antibody (Mab) and multiclonal hepatitis B virus surface antibody (Multiab) with hepatitis B virus surface antigen, which was coated on a pretreated glass slide. In the procedure, an optical transducer based transmittance interferometry was used to detect this interaction in real time. At the end of the interaction, an increase in protein layer thickness of about 7nm and 4.1nm for Mab as well as 6nm and 2nm for Multiab were obtained at the concentrations of 10 mug/ml and 1 mug/ml, respectively. The dynamic data derived from the film thickness change were evaluated with bimolecular model. Compared with the interaction between Multiab and antigen, higher kinetic constant between Mab and its corresponded antigen was obtained.