This paper gives a presentation of some recent works on the theme ``Constraints in term of stellar internal structure'' with emphasis on the results obtained by the members{ G. Alecian, A. Baglin, F. Bancken, C. Barban, G. Berthomieu, L. Bigot, G. Bisnovatyi-Kogan,T. Brown, C. Catala, T. Corbard ,M.A. Dupret, B. Foing , A. Gimenez, G. Gonczi, M.J. Goupil, G. Houdek, F. Kupka, Y. Lebreton, E. Michel, P. Morel, C. Neuforge, A. Noels, J. Provost, M. Rieutord, I. Roxburgh, R. Scuflaire, A. Thoul, S. Vorontsov, W. Weiss, J.P. Zahn } of the COROT sismogroup created after the Kick-off meeting (see http://dasgal.obspm.fr/~michel/COROT-SISMO.html for more information) involved in this theme. During an informal meeting which took place in November 1999 in Meudon, some actions to be done have been decided concerning: - the progress in stellar modeling by the introduction of radiative forces and the study of the limits of boundary of convective regions and -the relation between the limits of convective cores and the small frequency differences. A project of coupled inversion of structure and rotation involving two teams of the group has started up which is presented in the last section.