Cluster structures in light unstable nuclei are discussed. The structures of neutron-rich Be isotopes are theoretically investigated and the molecular orbital bond structure and its role in the vanishing of the neutron magic number N = 8 are discussed. The two-body cluster resonances in highly excited states of neutron-rich Li, Be and B isotopes are predicted theoretically. Cluster structures in light unstable nuclei are discussed. The structures of neutron-rich Be isotopes are theoretically investigated and the molecular orbital bond structure and its role in the vanishing of the neutron magic number N = 8 are discussed. The two-body cluster resonances in highly excited states of neutron-rich Li, Be and B isotopes are predicted theoretically.