Abstarct: In this study, structural, electronic and thermochemical properties of homo-A and A-co-FA and A-co-CA oligomers were investigated theoretically. The chain length of oligomers includes dimer, tetramer, hexamer and octamer. To perform mechanical quantum calculations, we used the density functional theory at B3LYP/6-311G* level of theory. The results of the structural calculations indicate that the torsional angles average between adjacent monomers along an oligomer chain leads a lower value with increasing oligomer chain for all neutral, cationic, and anionic states and molecules approach to the planar structure. The bridge angles average between the adjacent monomers along the cooligomer chain in the doped states increase compared with the neutral state. In the case of doped states, the length of single and double bonds along the π-conjugate system is closer to each with respect to the neutral state, indicating an improvement in the process of electrical charge transfer and conductivity in doped species. The results obtained showed that the energy gap between HOMO and LUMO decreases with increasing the length of oligomeric chain indicating an improvement in the conductivity in these molecules. In this regard, the energy gap values for both doped states (n and p), have more reduction than neutral ones. It is found that the rate injection of hole and electron is facilated with increasing cooligomer chain length. The thermochemical study of tixtled molecules was also showed that the stability of species increased as their chain length increased.