The report of Commission 12 presented here covers the parts of the field of solar physics other than those directly related to solar activities which, in our view, are the time-dependent phenomena inherent to solar active regions to be covered by Commission 10. From the sub-fields in the domain of Commission 12, the Organizing Committee selected six topics of special interest and invite six researchers to prepare reviews. Topics selected and reviewers are (1) Variations of Total Solar Irradiance ( Dr. R. C. Willson, Jet Propulsion Laboratory ), (2) Solar Global Oscillations ( Dr. E. Fossat, University of Nice ), (3) Magnetic Activity and Rotation in the Sun and Stars ( Dr. R. W. Noyes, Harvard University ), (4) Photospheric Magnetic Concentration and Related Problems ( Dr. H. C. Spruit, Max Planck Institut fur Astrophysik ), (5) Coronal Loop Structure and its Heating ( Dr. E. Priest , University of St. Andrews ), and (6) Coronal Transients ( Dr. E. Hildner, NASA Marshall Space Flight Center ). Of course it is not that there were no important contributions to the progress of sub-fields of solar physics other than those presented here. It was our consensus, however, that we should adopt this method since a complete coverage of works appearing across the entire field is no longer possible because of the rapid increase in the number of works in the expanding field of solar physics when severe page limitations exist for the IAU Reports.