Study of nuclear clustering by the use of antisymmetrized molecular dynamics (AMD) is discussed for both nuclear structure problems and nuclear collision problems. AMD enables us to describe both the mean field dynamics and the cluster formation. In the study of nuclear structure of light nuclei up to the neutron dripline, it presents us with a unique theoretical method which can describe both shell model structure and the cluster structure and the structure-change between the two. Capability of treating both the mean field dynamics and the dynamical formation of clusters is especially important in the study of heavy ion collisions at intermediate energies because the reaction process is dominated by various types of fragmentation mechanisms. ©2001 American Institute of Physics.