Quantum mechanics methods have been applied to study the conformational features of peptides formed by aminoxy acids. Geometry and vibration frequencies were calculated by the HF/6-31G** method. Energy was further evaluated using the MP2/6-31G** or B3LYP/6-31G*: calculation, Solvent effect was modeled by the self-consistent isosurface polarization continuum model with the HF/6-31G** method. There is a significant preference for the formation of an eight-membered-ring hydrogen bond between adjacent amino acid residues, which resembles a gamma-turn. The rotation direction of the C8 structure is determined by the chirality of the C alpha center and is independent upon the size of the alkyl side chain. There is a cooperative effect for the formation of adjacent Cs structures; which promotes the formation of helix. Thus, a homo (S)-oxa-polypeptide forms a right-handed 1.8-helix, with each turn of the helix containing about 1.8(8) units of aminoxy acids.