In an attempt to explore high efficient and cheap electrocatalyst for water splitting hydrogen production, small molybdenum carbide nanoparticles with the size about 3-6 nm are loaded on three-dimensional N-doped carbon matrix successfully with ammonium heptamolybdate ((NH4)(6)Mo7O24 center dot 4H(2)O) and filter paper as precursor by pyrolysis. Due to its small size, large surface area and high conductivity, this electrocatalyst shows excellent activity in hydrogen evolution reaction (HER). In acid media, its overpotential to achieve a current density of 10 mA.cm(-2) is as low as 167 mV, with Tafel slope is only 73 mV.dec(-1). The electrocatalyst also shows large exchange current density (j(0) ) with the value 0.15 mA.cm(-2). Furthermore, it shows excellent durability after 1000 cycles of long-term test, and the catalytic current remains stable over 10 h at fixed overpotential. This work elucidates a feasible strategy to obtain efficient electrocatalysts with cheap and naturally sustainable material as precursor and shed some light on the exploration and optimization of electrocatalysts in energy chemistry. The HER of this electrocatalyst is studied and the results illustrate it exhibits a stable hydrogen evolution rate of 44.5 mu mol.h(-1) with faradaic efficiency about 100%.