Metal-organic frameworks(MOFs)have crystalline structures and are typically characterized by large internal surface areas,uniform but tunable cavities,and tailorable chemistry.[1]MOFs have shown great promise for a variety of applications,including gas storage,chemical separation,catalysis and sensing.Particularly,the incorporation of functional materials,such as nanoparticles,small molecules,or even biomaterials,in MOFs has attracted great attention because of the benefits of the novel chemical and physical properties exhibited by certain classes of functional materials.In our group,we developed a serious of encapsulation strategies that allow many types of functional materials to be fully incorporated within crystals in a well-dispersed fashion.Our strategy relies on the successive adsorption of nanoparticles onto the continuously forming surfaces of the growing MOF crystals.The as-prepared hybrid materials exhibit both active(catalytic,magnetic,and optical)properties deriving from the incorporated functional materials and size-and alignment-selective behavior(i.e.,molecular sieving and regioselective guest reactivity)originating from the well-defined microporous nature of the MOF component.