The presented study carried out at Sids Agricultural Research Station, Wheat Research Department during three growing successive seasons (2017-2018, 2018-2019 and 2019/2020). The objectives of this investigation were to estimate the mean performances, gene action, heterosis, inbreeding depression and water deficit stress index under normal and water deficit stress conditions for grain yield and yield components. Six populations (P1, P2, F1, F2, BC1 and BC2) for the two crosses were coming from (Bani Suef 6 × Bani Suef 3) and (Bani Suef 5 × Sohag 4). Six parameters are estimated, i.e. means (m), additive (a), dominance (d), additive × additive (aa), additive × dominance (ad) and dominance × dominance (dd), the mean effects are highly significant for all studied characters in the two crosses, indicating that these traits are quantitatively inherited. For heritability values in broad and narrow sense were high and moderate in two crosses under normal and water deficit stress conditions. Meanwhile, inbreeding depression is positive and highly significant for all characters under normal and water deficit stress conditions. In the two crosses, regarding potance ratio values are more than unity for all characters under study except number of spike plant-1 with second cross. For evidences of water deficit stress tolerance, the results indicated that the two parents involved in the second cross were low sensitivity to water deficit stress, so that most of the generations from the second cross had low values at both TOL and YR