The detailed structural analysis of fibrous carbon electrode materials modified by Cu or Cu3P particles is designed for hydrogen evolution reaction (HER). Two different calcination temperatures and reduction atmospheres were used in order to uncover the most effective catalytic electrode material. The novel families of carbon fibrous electrode materials were prepared by low-cost and versatile needle-less electrospinning process. The chemical structure of prepared modified fibers was analyzed by XRD, C-13 and P-31 NMR spectroscopy. The morphology of the final samples and the location of Cu or Cu3P micro and nanoparticles were observed by SEM and TEM tomography. TEM XEDS mapping revealed the exact position of Cu, P, C and O elements within the matrix of fiber. The electrocatalytic activity for HER was evaluated by the linear sweep voltammetry, impedance spectroscopy and Tafel slopes analysis. The highest performance for HER was observed in the carbon fibers incorporating copper or copper phosphide nanoparticles thermally treated in argon atmosphere at 1000 degrees C and successively in hydrogen reduction atmosphere.