Cosmology has developed in SAp along the following two lines: observational cosmology which has benefited from the commissioning of new observatories both in space, like HST, ISO, Chandra and XMM, and on the ground, such as the Keck Telescope or VLT, and numerical simulations which has benefited from the availability of large parallel computers in CEA. On the observation side, the main activities have been focused on the use of ISOCAM and X ray observatories to study galaxy evolution and cluster of galaxies physics. On the simulation, the efforts have been directed toward the development of new hydrodynamic codes adapted to the formation of large scale structures in the Universe. In addition to these activities, there also some theoretical works done on space-time.