A bronze processed multifilamentary Nb/sub 3/Sn superconducting wire with CuNb reinforcing stabilizer (CuNb/Nb/sub 3/Sn), which exhibits a residual resistance ratio of 20 and a magnetoresistance of 0.2 mu Omega -cm at 23 T and 4.2 K, has been developed. The yield stress at 4.2 K, was noticeably improved; a value of 22 kg/mm/sup 2/ was obtained even after heat treatment of Nb/sub 3/Sn formation at 700 degrees C for 200 h. The effect of strain on critical current density, J/sub c/, was described well by using the upper critical field in the prestrain state. It was verified that the CuNb/Nb/sub 3/Sn wire mechanical and superconducting properties need to perform under an enormous electromagnetic force in high magnetic fields.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>