Ni-YSZ cermet have widely been investigated as fuel electrode of solid oxide electrolysis cells (SOECs). It is accepted that higher density of reaction sites, so-called triple phase boundaries (TPBs), within the limited electrode area provides efficient hydrogen generation. Since the cermet is usually fabricated through in-situ reduction of sintered NiO-YSZ composite at initial stage of operation, TPB density strongly depends on the size and distributions of NiO and YSZ in raw material. The present study focuses on the pre-fabrication of NiO-YSZ nanocomposite particles as raw material of hydrogen electrode through an aqueous co-precipitation approach. The effect of growth parameter on the yields of each element, microstructure of the composite particles, and resulting performance of fuel electrode were characterized in detail. The reaction products were collected with the yield of about 90% above pH8 of the reaction solution. The volume content of YSZ could be precisely controlled in the range 40-80% of cermet under the optimized conditions. The nanocomposite particles yield homogeneous porous microstructure of the Ni-YSZ cermet with the grain size of about 200 nm diameter. Relatively low polarization resistance of 0.29 Ω·cm-2 at 800 ºC under 20% H2O- H2 atmosphere can be attributed to large TPB density.