The design of efficient,stable,and economical electrocatalysts for oxygen and hydrogen evolution reaction (OER and HER) is a major challenge for overall water splitting.Herein,a hierarchical structured CoP/carbon nanofibers (CNFs) composite was successfully synthesized and its potential application as a high-efficiency bifunctional electrocatalyst for overall splitting water was evaluated.The synergetic effect of two-dimensional (2D) CoP nanosheets and one-dimensional (1D) CNFs endowed the CoP/CNFs com-posites with abundant active sites and rapid electron and mass transport pathways,and thereby signif-icantly improved the electrocatalytic performances.The optimized CoP/CNFs delivered a current density of 10 rnA cm-2 at low overpotential of 325 mV for OER and 225 mV for HER.In the overall water splitting,CoP/CNFs achieved a low potential of 1.65 V at 10 mA cm-2.The facile strategy provided in the present work can facilitate the design and development of multifunctional non-noble metal catalysts for energy applications.