With the development of wearable augmented reality (AR) technology, there has been a growing emphasis on 3D user interfaces that allows users to interact with virtual objects. Interaction with a subspace, containing objects of interest and their peripheral areas, provides clue that is used to overcome restrictions of interaction with a distant object in AR scene. Egocentric interaction techniques that enable selection and manipulation of a target subspace are required prior to applying user interactions for a distant subspace. In this dissertation, we study on interaction techniques of selection and manipulation of a distant subspace in wearable AR environment. Before designing a method of subspace selection, it is necessary to define the features of subspaces which are determined by user input on the egocentric viewport. Based on the features of the subspace, we propose TunnelSlice, which supports freehand gesture inputs, for effective acquisition of a subspace at a distance via head-worn display even for scenarios involving ambiguous central objects and occlusion. We also propose a freehand based Subspace-in-Miniature, which utilizes subspace replicas, for effective access to and rapid manipulation of 3D objects of interest at a distance. We expect that proposed methods allows user-driven cutout interactions such as subspace authoring, subspace sharing, and subspace management in education, tour, interior, games, and filmmaking with wearable AR technologies.