Abstract
We discuss the recent development of formation of mesoscopic structures and kinetics of morphological transitions in soft matter. Special attention are paid to the so-called interconnected bicontinuous structures such as a gyroid. It is stressed that there are often intermediate metastable structures in the process of the morphological transitions. In particular, we describe Fddd structure and a perforated lamellar structure comparing the experiments of water-surfactant systems and block copolymers. The unsolved future problems are also emphasized.