Nanobiodevice is a piece of contrivance, equipment, machine, or component, which is created by the overlapping multidisciplinary activities associated with nanotechnology and biotechnology, intended for biological, medical, and clinical purposes.During the past decade, nanobiodevice has progressively begun to focus on the establishment of main four fields of biomedical applications of nanotechnology, including 1) diagnostic devices, 2) molecular imaging, 3) regenerative medicine, and 4) drug delivery systems.In this lecture, I will describe the development of nanobiodevices to analyze biomolecules and cells towards biomedical applications.[1-10] I developed numerous diagnostic nanodevices based on the single biomolecular separation and detection.These devices are also applicable to fast and low invasive blood marker detection of cancer with pM-fM detection sensitivity.Additionally, I developed new synthetic method of quantum dots (QDs) based on the appropriate cluster confirmation by the ab initio molecular orbital calculation.QDs are applied to the development of nanobiodevice for single cancer cell diagnosis, single molecular epigenetic analysis, in vivo imaging for stem cell therapy and theranostic device for cancer diagnosis and therapy.