The amino acids; L-alanine, OL-aspartic, L-cysteine, Leglutamic, L hydroxyproline, L-phenylalanine and L-proline were evaluated for their efficacy against the root-knot nematode, Meloidogyne incognita , and in improving growth of the infected soybean plants. Foliar spray applications of three concentrations of the tested amino acids revealed their potent effects on the nematode development and reproduction. However, variability in such effect was, obviously, noticed linking with properties of the amino acids and the used concentrations. Conclusively, the nematode final population and its rate of build up were decreased in most amino acid treatments in comparison to those of the check. Also, significant improvement in growth parameters of the infected soybean plants were obtained by most amino acids applications. However, no or little adverse effect on growth parameters was noticed. Hence, it is suggested that amino acids specially L-alanine , L-cysteine, L-glutamic and L-hydroxyproline at their suitable concentrations may affect directly and/or indirectly the invaded nematodes by inducing a variety of resistance to the host.