The brief review of the main methods for Giant Dipole Resonance (GDR) experimental research and of main results obtained is presented. The specific treatment is devoted to the yields and cross sections (excitation functions) of total photonuclear reactions and also of partial reactions corresponded to the various GDR decay channels. Main attention is devoted to the features of experiments carried out using various photon beams, first of all that of bremsstrahlung and relativistic photons annihilation in flight because majority of published data has been obtained using these methods. Additionally the main methods of different photonuclear reaction, first of all of photoneutron reaction with different neutron multiplicity, identification are analyzed. The systematical uncertainties caused by these features and correspondent systematical discrepancies between the results of various experiments concerned are investigated for both total and partial reactions. The methods of taking into account and excluding of such kind uncertainties are proposed. The possibilities of estimation and evaluation of the main GDR parameters with much more higher accuracy based on the systematical discrepancies under discussion excluding are discussed.