Ga NMR study of GdGa2-xAlx

69Ga and 71Ga NMR signals in GdGa2-xAlx (x = 0.1, 0.25, 0.5, 0.75,1) have been observed at a low temperature in a zero magnetic field. Gd NMR signals were observed only for the samples with x ≤ 0.5 in the frequency range less than 110MHz, but Ga NMR signals have been observed for all samples in the frequency range higher than Gd NMR frequencies. The features of the observed Ga NMR spectra of the samples with low Al concentration are quite different from those of highly Al concentrated samples. This difference is attributed to the change of the magnetic structure of these compounds. NMR parameters calculated from the Ga NMR results are reported, too. The magnetic structures of these compounds are discussed on the basis of the Ga NMR results.