Here we show how a high-resolution transmission electron microscopy can be applied to characterize the carbon nanostructures. Direct imaging of the hexagonal network of carbon nanotube enables us to determine the chiral index and to visualize the topological defects, such as pentagons and heptagons. Individual molecular imaging has also become possible, and atomic structure of fullerene molecules (C60 and C80) has been successfully identified at a single-molecular basis. Some recent progress for in situ observation of the carbon nanotube/fullerene growth and the defect dynamics is also presented. © 2012 Pan Stanford Publishing Pte. Ltd. All rights reserved.