The AMMO environment (Authoring and Manipulation of Multimedia Objects), has been developed to provide the storage and manipulation of multimedia applications based on the MHEG-5 and SMIL standards. In this paper, the information involved in the representation of multimedia applications, as well as the characteristics of the semantic searches — exact and fuzzy — provided in the AMMO environment are presented. These features allow retrieving media objects Audio, Bitmap, Video and Text and applications based on the MHEG-5 or SMIL using uniform query formulation. A wide range of queries that a user can use to carry out his search in the AMMO’s multimedia data base is made available by keeping. The AMMO’s multimedia data base can be searched through a wide range of queries, this is possible by keeping together the semantic information and the multimedia metadata..