The errors may be introduced in the process of measurement and evaluation for preparing radial distribution function (RDF), They will cause the error distortion that RDF can be partly upset. RDF method is based on structual isotropy of amor-phous materials, however, a structural anisotropy, i.e orientation, hes been found in amorphous polymeric, inorganic and metallic materials. The orientation will greatly affect RDF, and will lead to a new distortion that RDF may be wholly upset. Obvirously, if it is not given due regard, a misinterpretation on RDF can occur. The feature of the so-called orientation distortion is discussed in the present paper.