The primary objective of an exoskeleton robot varies depending on its application. For assistive exoskeletons, the goal is often to enhance their physical capabilities based on a given task and human motion intention. In contrast, rehabilitation-based exoskeletons may focus on providing specific resistance or assistance to promote effort, motor learning, and recovery. In both applications, considerable data is generated during the physical interaction between the human and the robot. This chapter discusses the assistive application and presents the results of how the robot shapes and improves its assistance via interaction learning (that is, obtaining and utilizing data via physical interaction, dealing with potential conflict during the interaction, and improving the wearer’s comfort and the robot’s assistance). The content covers both the lower limb and the upper limb exoskeleton robots, where the former supports the body weight, and the latter augments the manipulation ability.