Molecular gas is a major component of the interstellar medium of the Milky Way Galaxy. Molecular cloud are the main environment in which stars form, so elucidating their spatial distribution and formation mechanism in the Galaxy is an important research field. Recent advances in interferometer observations have identified numerous macromolecular clouds in extragalactic galaxies, and research into their physical state, star formation, and evolution is progressing. However, it is also necessary to understand the lower mass molecular clouds that constitute the bulk of the molecular gas. In order to study the molecular gas structures over such a wide dynamic range, we use the CO survey (FUGIN) data obtained for the inner region of the galaxy and developed a method to identify molecular cloud structures. About 400,000 molecular gas structures were identified, and about 35,000 structures were selected as molecular cloud candidates. The masses range range from 50 to 3 million solar masses, and the sizes range from 0.5 pc to 70 pc. In this talk, I will introduce the details of the selection method of molecular cloud candidate objects and report on the physical properties and states of the selected molecular clouds. I will also discuss the spatial distribution of molecular clouds in galaxies.