Atomic force microscopy (AFM) has been used for surface study of nanomaterials and biosamples. It is suitable to study bioscience because it has nanometer resolution, good sensitivity and also can be used in aqueous solution for various applications. In this study, AFM is used for analyzing the force-distance curve between the anti-BSA tip and BSA substrate. We use the interaction between the anti-BSA and BSA to achieve the technique of molecular recognition.