Physical phenomena at macroscopic levels have been extensively explored in past decades, and many notable technological breakthroughs have been made. When the dimension of materials is reduced down to nano-meter scales (<100 nm), such as quantum dots, nano-particles, nano-wires and nano-tubes, many peculiar phenomena are observed, which cannot be readily understood by traditional theories. In fact, many traditional theories for material strength, for example, grain-boundary strengthening (or the classical Hall-Petch relationship), begin to break down as the characteristic length of a material approaches the nanometer range. The so-called "size effect" has been not only observed and vigorously studied in many functional materials (magnetic, optical, electronic) but also in structural materials in recent years. The time is now mature to expect breakthroughs of our fundamental understanding of the structure-performance correlation in nanostructured materials under complex application environments. These are all fundamental issues, and we anticipate that this GRC will provide a good platform for scientists to share their interesting observations, discuss the physical underpinning mechanisms, and address the technological implications. As is the tradition of the Gordon Research Conferences, the meeting is founded on several fundamental pillars: to represent the frontiers of science, to present unpublished and speculative work, and to engage world-class speakers. The series of nine topical areas over four and a half days of technical presentation are summarized below. The list of speakers and discussion leaders is presently being assembled with a view toward invitees with international stature, as well as a balance between senior and junior researchers. A goal of the organizers is to have strong participation by under-represented groups among the speakers and leaders, and to also provide ample support and encouragement for students, post-doctoral researchers and early career professionals. This particular GRC conference will be held in Hong Kong, because its location and history as meeting point of East and West making it an ideal place to coordinate the global activities in the field.