Self-assembly and biomineralization are key processes in the formation of many composite biological materials. In the present study, a peptide-based network was designed based on P11-4 (P), a 11-amino acid peptide that self-assembles into a nanofiber network and a genetically engineered peptide that selectively binds to inorganics (GEPIs, 7 amino acids: AcNH-Asn-Asn-His-Tyr-LeuPro- Arg-NH2) to investigate its ability to induce mineralization. Transmission electron microscopy (TEM) and selected-area (SAED) analysis demonstrated that the E/GEPI-P11-4-E/ GEPI (E-P-E) peptide undergoes folding and assembling in response to a specific pH change and is capable of directing the formation of hydroxyapatite. The findings for the control peptides either lacking the mineralization-directing portion or with the E/ GEPI on only one side indicated that each sequence is necessary to the properties of E-P-E and has a specific function. The FTIR results suggested that the self-assembling peptide can influence mineralization in dental tissue engineering applications. In summary, the 25-amino acid E-P-E peptide was shown to self-assemble into a nanofiber network and applied to form an organic/inorganic hierarchical nanocomposite material after mineralization in which the crystallographic c axes of hydroxapatite were aligned with the long axes of the nanofibers.