Carbon micro/nanofibers prepared by catalytic chemical vapor deposition have been characterized using scanning electron microscopy, transmission electron microscopy, high resolution electron microscopy, electron spectroscopy for chemical analysis and Raman spectroscopy. The outer diameter of the fibers varied from 50 nm to 600 nm with an average diameter of 120 nm, length from several micrometers to several tens of micrometers and inner diameters from 20 nm to 230 nm. Two types of fibers have been identified: cylindrical and bamboo-shaped. The cylindrical fibers are usually defect-free and consist of distinct graphite layers parallel to the fiber axes. The bamboo-shaped fibers often contain defects at the nano-level, their walls are built from domains with different orientations of graphite layers.K e y w o r d s : carbon micro/nanofiber, cylindrical fiber, bamboo-shaped fiber