Although the nuclear emulsion technique no longer enjoys the position it had in the past, when many important discoveries were made using emulsion, however, high spatial resolution and the high discriminating power because of the ability to make direct high precision and reproducible microscopic measurements on track structure in emulsion as well as the relative ease of handling the emulsion are special advantages. Nuclear emulsion is still favoured for use in special studies in hypernuclear physics, cosmic rays, autoradiography and other applications. The study of the structure of tracks produced in nuclear emulsion provides information about the mass, charge and velocity of the particles producing the track. The axial as well as radial structures of the tracks have been studied extensively. Over the years these track structure studies have been greatly refined to yield accurate and reproducible values of the particle parameters. Classical methods of identification of particles in nuclear emulsion as well as recent work on track structures are briefly reviewed.