Owing to the adjustable characteristics and superior etching properties of co-sputtered Nbx Si1-x film, we are trying to fabricate Nb/Nbx Si1-x/Nb Josephson junction arrays for voltage standard. It is important to find the suitable Nbx Si1-x barrier for the junctions. Josephson junctions with different barrier content are fabricated. Current–voltage characteristics are measured and analyzed. It is demonstrated in this paper that critical current can be adjusted by using different barrier content