Organic molecules are the proficient materials which have been used in Organic field effect transistors and organic thin film transistors. Among the extensive range of ET materials reported in the literatures, the materials based on oxadiazole were supposed to be among the most effective ones. This book deals with Density Functional Theory (DFT) which is well suited to explore the properties of the conjugated π-electron systems. We report the ground-state geometry optimizations of newly designed oxadiazole based oligomers using the DFT method with B3LYP functional and 6-31G** basis set. The relevant absorption spectra computed at the TD-B3LYP/6-31G** level of theory. The electronic, photophysical and charge transfer properties have been discussed in detail. The effect of electron deactivating group at different positions has been investigated and discussed.