In current study, we report the direct interaction force comparison for a synthesized peptide probe to actin and cofilin protein to actin using atomic force microscopy. The peptide probe was synthesized following the actin binding module of cofilin protein. Thus, the functionality of the peptide probe was similar with that of the cofilin protein. The difference between the peptide probe and cofilin protein was the molecular size. The small peptide probe enables highly dense surface modification, thus produces different interaction force curves compared with that of original cofilin protein to actin. The results showed the peptide probe was possible to measure many numbers of the interaction force though the measurement of single molecular order interaction force was a weak point. These imply that the peptide probe has a merit when that was applied surface related applications such as protein sensor and protein-protein interaction separation.