Transition-metal based hybrids with excellent stability and activity are favorable candidates for hydrogen evolution reaction (HER).The development of typical Co3S4 has recently received considerable atten-tion due to the multiple valences of the spinel-structured compound.However,the in-depth effect of the dopants on the HER performance of Co3S4 has not been systematically clarified.Here,we report a sequential synthesis of a spinel-structured cobalt phosphosulfate nanoneedle arrays grown on carbon cloth (namely,P-Co3S4/CC).Results indicate that P-Co3S4/CC exhibits high electrocatalytic performance for HER with a low overpotential of 65 mV to drive10 mA cm-2,a small Tafel slope of 76.6 mV per decade,and great long-term stability for 25 h at various current densities in alkaline electrolyte.The first-principle calculation result reveals that the phosphorous doping work at Co3S4 enhances the HER performance sig-nificantly because the tetrahedral Co2+ active sites nearest the P atoms more easily weaken the H-O bond to form intermediates.The experiment result characterization and theoretical calculations further show that the introduction of P atom not only offers more active sites but also improves the electrical con-ductivity in an alkaline electrolyte solution.Consequently,the identification of active species provides feasible guidance for the further design of high-performance spinel-structured catalysts.