Multifilamentary Nb3Al superconducting wires for high field magnets above 20T have been developed by a rapid-quenching process. A wire of long length was fabricated. A coil was fabricated using the wire. Jc of this wire was 195A/mm2 at 20T,4.2K and 486A/mm2 at 20T,1.8K, Bc2 of the coil was 24.6T at 4.2K and 26.9T at 1.8K and the Tc was 17.8K. In addition, to investigate stability the RRR was measured, the value was 16.9. Scattering of the Jc in the longitudinal direction was examined and found to be within ± 10%.