In this study, the performance of an aqueous extract of fenugreek seeds (AEFS) as an inhibitor of alpha-brass corrosion immersed in 1 M HNO3 was investigated by mass loss technique, the results showed that the inhibition efficiency increases to reach 96.48 percent at 10 percent of (AEFS) with increasing concentration. The impact of temperature on alpha-brass corrosion conduct immersed in 1 M HNO3 without and with the inhibitor was tested in the temperature range of 303 and 343 K at 10 percent of (AEFS). Various adsorption parameters (Ea, G°ads, Kads) show a strong interaction between the inhibitor and the surface of the alpha-brass. The Langmuir adsorption isotherm was obtained by the adsorption of (AEFS) on the alpha brass surface. The surface analysis was performed using an electron microscope scanning technique that confirmed the formation of a protective layer in the presence of the extract on the metal surface.