Recently, the HCI community has seen an increased interest in applying Virtual Reality (VR), Augmented Reality (AR) and Mixed Reality (MR) into educational settings. Despite many literature reviews, there still lacks a clear framework that reveals the different design dimensions in educational Extended Reality (XR) systems. Addressing this gap, we synthesize a broad range of educational XR to propose the XR-Ed framework, which reveals design space in six dimensions (Physical Accessibility, Scenario, Social Interactivity, Agency, Virtuality Degree, Assessment). Within each dimension, we contextualize the framework using existing design cases. Based on the XR-Ed Design framework, we incorporated instructional design approaches to propose XR-Ins, an instruction-oriented, step-by-step guideline in educational XR instruction design. Jointly, they aim to support practitioners by revealing implicit design choices, offering design inspirations as well as guide them to design instructional activities for XR technologies in a more instruction-oriented and learner-centered way.CCS Concepts: • Human-centered computing → Mixed / augmented reality; Virtual reality; Interactive systems and tools; • Applied computing → Interactive learning environments.