The present invention relates to a method of systematically and synthetically accessing modality conversion that is an important part in the contents adaptive conversion process of a universal multimedia access system. The present invention provides an effective method of solving a problem, which is incurred at the time of modality conversion and still remains as one of difficult problems incurred during adaptive contents conversion. For this purpose, the present invention includes overlapped contents modeling newly proposed to determine modality conversion, a method of flexibly and clearly expressing and applying user preference for the modality conversion, and a resource allocation method of distributing resources among complicated contents based on the user preference. As a result, the integration of the above three methods provides a synthetic solution, particularly, to a problem incurred in the modality conversion and, generally, to a problem incurred in the adaptive conversion of contents.