Molecular imaging is a new subject of exploring the biological metabolism process of the cells or organs in living organisms with some non-invasive technologies, such as PETE-CT, MR, and optical imaging instruments, using specific molecular probes to investigate the pathologic and physiologic metabolisms of the patients at molecular and gene levels. With the development of this technology, molecular imaging plays a more and more important role in guiding cancer chemotherapy, choosing sensitive medicines, planning treatment scheme, evaluating chemotherapy effect, and so on.