Toll-like receptor 2 is an important pattern recognition molecule of innate immune, which could recognize diverse pathogens and their products. Using the eukaryotic expression TLR-2 extracellular fragment as target to screen peptide mimics to ligand of TLR-2 from Ph.D.-12 phage display peptide library, 20 of positive phage clones were sequenced , which shared a very conservative sequence and was named as P12-1. Biotinylated peptide P12-1 could bind with different form of TLR-2 extracellular fragment, and also stimulate THP-1/CD14 cells to secrete TNFα. These results indicated that P12-1 could mimic the structure and activity of ligand of TLR-2.