Fast beams of radioactive isotope (RI) have been used for nuclear spectroscopy at RIKEN since 1990. Various direct‐reaction experiments have been performed at intermediate‐energies in the reversed kinematics to study structures of nuclei very far from the stability valley. Several examples of recent results on neutron‐rich nuclei around N=20 and carbon
isotopes are presented. The RIKEN RI Beam Factory, which will have the first beam in the end of 2006, will greatly extend the region of study to more exotic and heavier nuclei.