Abstract Porous crystals such as metal–organic framework (MOF), porous coordination polymer (PCP), and porous organic crystals have shown promise as solid materials in terms of their great potentials for catalysis, separation and refinement techniques, environmental protection, nanoengineering, and pharmaceutical applications. Here we discuss cavity-assembled porous solids (CAPSs) formed as the result of self-assembly of macrocycles or cage compounds possessing well-defined binding cavities for guest molecules. In addition to conventional macrocycles such as cyclodextrin, crown ether, cucurbituril, calixarene, cyclotriveratrylene, pillararene, and organic cages, we have recently reported a novel crystalline nanochannel (metal–macrocycle framework: MMF) composed of macrocyclic trinuclear PdII complexes with tris(o-phenylenediamine)cyclophane. This account focuses on how cavities with guest-binding capability assemble to form porous structures taking recent examples.