In the as-quenched condition, the microstructure of the Cu-14.6Al-4.3Ni alloy is DO3 phase containing extremely fine precipitates. Transmission electron microscopy examinations indicated that the extremely fine precipitates are L-J phase, rather than 2H phase. In addition, electron diffraction analyses indicated that the L-J precipitate has two variants with the DO3 matrix. These results are quite different from those reported by other workers in a Cu-14.2Al-4.3Ni alloy.