An investigation on the subject of evolution of propagation diagrams and obtaining the theoretical frequency spectrum of some delta Scuti star models with masses around 2 M-circle dot has been presented. The variations of some eigenfunctions throughout the star, the variation of omega(2) with logT(e) and the distribution of nodes of eigenfunctions of some modes along with the evolution of the star have been plotted and examined. For the models at the ZAMS phase, pure acoustic modes in the outer stellar layers and pure gravity modes in the interiors were calculated. A mixed character of low degree nonradial modes was found in evolved models. These modes behave like p modes in the envelope and like g modes in the interior.