The interfacial phenomena of proteins with regard to surfaces play a significant role in the determination of the success of implantation. In this study, we investigated the interfacial behavior of model proteins, such as bovine serum albumin (BSA) and lysozyme (LZM) on the surface-modified silica surfaces. Adsorbed mass of proteins on each surface was classified into two categories: loosely bound and tightly bound states. The adsorbed mass of each protein was quantified in terms of adsorbed mass per unit surface area using Q sense. The result displayed that the negatively charged BSA adsorbed less than positively charged LZM. Amount of the tightly bound LZM was greater than that of BSA. Adsorption behavior of oppositely charged proteins demonstrated that the adsorption is considerably affected by the charge of protein molecule and surface. This study proposes that interfacial behavior of protein molecules should be studied more in detail in order to improve understanding on the functions of drugs and biomaterials.