Recently an international standard for Multimedia content description, MPEG-7, has been finalized in the 1st phase by reaching the FDIS level. MPEG-7 aims at providing structural and semantic description mechanism for multimedia contents so that content based searching/filtering and access to multimedia content can be possible in conjunction with multimedia description data, that is, MPEG-7 description data. However, the MPEG-7 specifications only specify the syntax and semantics of describing multimedia contents but not authoring content description data. In this paper, we introduce an MPEG-7 metadata authoring tool that can be used in generating MPEG-7 metadata data for multimedia contents. The MPEG-7 metadata authoring system has a generic architecture for MPEG-7 based metadata authoring but mainly relies on MPEG-7 Multimedia Description Schemes for multimedia description generation.