Preface. Reports of Commissions. Ephemerides. Documentation and astronomical data. Astronomical telegrams. Celestial mechanics. Positional astronomy. Instruments and techniques. Solar activity. Solar radiation and structure. Atomic and molecular data. Physical study of comets, minor planets and meteorites. Physical study of planets and satellites. Rotation of the Earth. Positions and motions of minor planets, comets and satellites. Light of the night sky. Meteors and interplanetary dust. Photographic astrometry. Stellar photometry and polarimetry. Double and multiple stars. Variable stars. Galaxies. Stellar spectra. Radial velocities. Time. Structure and dynamics of the galactic system. Interstellar matter. Stellar constitution. Theory of stellar atmospheres. Star clusters and associations. Exchange of Astronomers. Radio astronomy. History of Astronomy. Close binary stars. Astronomy from Space. Stellar classification. Teaching of Astronomy. Cosmology. High energy astrophysics. The interplanetary plasma and the Heliosphere. Protection of existing and potential observatory sites. Bioastronomy: search for extraterrestrial life. Working Group for Planetary System Nomenclature: WGPSN. Working Group for the World Wide Development of Astronomy: WGWWDA.