The research on the stabilization of polyacrylonitrile (PAN) fibres gains more interest as they are the most commonly used precursor for carbon fibre production. As the carbonization requires temperatures up to 1600°C the precursor has to be converted into a ladder polymer structure with high thermal stability, which is done in a stabilization step. Due to the high exothermic behavior of the stabilization reaction, the whole process has to be carried out using an energy and time-consuming regime. In this study, the electron beam (EB) treatment was evaluated for stabilizing the PAN precursor fibres after their wet spinning. It is commonly known that morphology such as crystallinity, polymer chain orientation and porosity plays a crucial role on fibre properties, which influences the stabilization behavior of carbon fibre as well. Morphologies role in electron-induced chemical reactions was studied as well as the electron-induced changes on the morphology. Therefore PAN powder and fibres with different porosities and crystallinities between 60% and 80% were treated above and below the glass transition temperature with various doses. All experiments performed below the initiation temperature of the stabilization reaction, to analyze only electron-induced reactions. In order to understand the dependency of electron-induced reactions on the initial morphology, the crystallinity, crystal size equivalent and orientation were contrasted with BET, EPR, TGA, DSC and FTIR measurements, showing significant changes of results from powder to fibre. The investigations have shown that the general crystallinity of material decreases with increasing dose while the crystal size equivalent increases. Not every investigated lattice plane responses in the same way, therefore electron-induced morphology rearrangement seems to be dependent on the orientation which has to be considered for highly oriented fibres.