Periostin, a component of the extracellular matrix expressed by fibroblasts in normal tissues and stroma of primary tumor, is associated with asthma, chronic allergic inflammation, and metastatic colony formation. The four internal repeat fasciclin I (FAS1) domains of periostin play an important role in cell adhesion and tumor metastasis by interaction with integrins. At the N-terminus, periostin has a cysteine-rich EMILIN (EMI) domain which is involved in various protein-protein interactions. The gene of the FAS1 domains of human periostin were systemically constructed and their expression were tested using E. coli expression system. Although all FAS1 domains were well expressed, only FAS1_II and IV were soluble. The structural characteristics of FAS1 domains was studied by circular dichroism (CD) and nuclear magnetic resonance (NMR) spectroscopy. CD studies clearly showed that FAS1_II and IV domains were composed of α-helix and β-sheet structure, which is consistent with a previously determined FAS1 domain from Drosophila melanogaster. NMR studies showed that FAS1_II and IV domains are well folded. We almost completely assigned backbone and sidechain resonances using 3D NMR spectroscopy and determined the structure of FAS1_IV domain. To develop the peptide inhibitor of periostin, we performed screening of novel peptide ligands binding to FAS1 domains using one-bead one-compound combinatorial libraries.