The implementation of an augmented reality game suffers from the weak support of existing editing tools for augmented reality natures. This article proposes a 3D space authoring tools specialized to interactive augmented reality games. First, a game designer prepares 3D models using classical 3D authoring tools. Then the augmented reality authoring tool loads the 3D models and groups them into component parts. A group of 3D models corresponds to a logical component of the augmented space. Attributes of a group are edited in a convenient way using the authoring tool. A game designer places each group of models in a proper position and sets the group properties. Each group can be dynamic and interactive and have a scenario. A scenario consists of a set of states and a set of state transitions. State transitions are caused by position movements, collisions, elapsed time, or appearance of markers. The designer can visualize the current game space during the authoring process and can save the contents to a single file when the editing is completed. The saved space file is loaded by an augmented reality game as an interactive game space. The proposed authoring tool supports game designers to make various interactive augmented spaces in a fast and convenient way.