Activated carbon (AC) supported tungsten carbide was reported for the catalytic decomposition of hydrazine for the first time. It was found that the WC (x) /AC-H catalyst prepared by a carbothermal hydrogen reduction process exhibited excellent catalytic performances both in the microreactor and in a 1 Newton hydrazine microthruster. The XRD, TEM and microcalorimetry results suggest that the formation of well crystallized W2C phase, the restraining of the carbon deposition, as well as the prohibiting of the methanation should be responsible for the high activity and stability of the WC (x) /AC-H catalyst in the hydrazine decomposition reaction.