1. An authoring system for supporting the creation and editing of an action of a multi-joint structure comprised of a combination of a plurality of chronological data, comprising: a user inputting unit for inputting commands or data from a user; a user presenting unit for presenting an editing area in which chronological data making up the action are arrayed chronologically along the time axis; and a chronological data editing unit provided for each chronological data making up the action, said chronological data editing unit creating or editing relevant chronological data based on a user input through said user presenting unit.