In this report, the poly(Tyramine) (PTyr) film structure was further studied and determined, based on IR (Infrared), XPS (X-Ray Photoelectron Spectroscopy), EQCM (Electrochemical Quartz Crystal Microbalance) results. Especially, the immobilization capacity of PTyr was investigated by EQCM in situ measurement. The results showed the film porosity had increased the immobilization capacity of PTyr, compared to other polymer film with the same NH2 surface concentration.