In this talk, we propose an approach to the design and synthesis of “giant molecules” based on “nano-atoms” for engineering structures across different length scales and controlling their macroscopic properties. The “nano-atoms” are referred to a group of shape-persistent molecular nanoparticles (MNPs) with precisely-defined chemical structures, shape symmetry, and surface functionalities that can serve as elemental building blocks for the precision synthesis of “giant molecules” by methods such as a sequential/one-pot click approach. The resulting “giant molecules” are precisely-defined macromolecules. Typical “nano-atoms” used in this study include those based on fullerenes, POSS, polyoxometalates, and folded globular proteins. The “giant molecules” constructed are those of giant surfactants, giant shape amphiphiles, and giant polyhedral, to name a few. Giant surfactants are composed of “nano-atoms” tethered with flexible polymer tail(s) of various compositions and architectures at specific sites with amphiphilicity. Giant shape amphiphiles are built up by covalently-bonded “nano-atoms” having distinct shapes. Their self-assemblies are driven by both the shape of the “nano-atoms” as well as the chemical interaction. Giant polyhedra are either made of a large MNP or by deliberately placing “nano-atoms” at the vertices of a polyhedron. “Giant molecules” capture the essential structural features of their small-molecule counterparts in many ways but possess much larger sizes; therefore, they are recognized in some cases as size-amplified versions of those counterparts. Highly diverse, thermodynamically stable and metastable hierarchal structures are observed in the bulk, thin-film, and solution states of these “giant molecules”. All the results demonstrate that MNPs are unique elements for macromolecular science, providing a versatile platform for engineering nanostructures that are not only scientifically intriguing, but also technologically relevant.