To assess a Ni-clad melt-processed YBa2Cu3Oy (YBCO) conductor approach, a systematic study was made on commercially available YBCO powder mixed and co-sintered with nickel oxide (NiO). Our research effort has focused on the effect of nickel on the critical current density in the YBCO/Ni composites. Four series of YBCO samples mixed with 0.3, 0.7, 1, 1.3, 2 and 3 wt% of high purity NiO were prepared, and optimized conditions for the melt process were established. These samples were characterized by resistivity, AC susceptibility and DC magnetization measurements. The highest magnetization critical current density (Jcm∼3×105 A/cm2 at T=4.2K and H=0 was observed in melt-processed samples with ∼ 1 wt% Ni (or -1.3 wt% NiO) subjected to a cooling rate of 2°C/hr from 1040°C to 980°C. This Jcm was found near the middle of the Ni-solubility range (about 2 wt% Ni is the solubility limit of Ni in YBCO) which may be attributed to the local Ni/Cu compositional fluctuation leading to an increased pinning force density in these composites.