Over the past decade, seismic reflections profiling across oceanic lithosphere and ODP have produced spectacular images of extensional structures within the crust and upper mantle. Recent studies in several ophiolite complexes have found evidences for extensional structures on the ocean floor prior to emplacement into continental margin, for examples gabbroic mylonite, rotation of the dike swarm. This paper introduces a few typical ophiolite complexes in the world, and points out that the extensional structures of ophiolite recorded rich information for the forming, spreading and closing process of paleo-crust. So the studies of extensional structures in ophiolite will have important significance for the tectonic evolution of paleo-oceanic crust.