GC-MS is a test that has been done to determine the compounds contained from a material. In this study, we analyzed the characteristics of the inhibitory process of mango peel skin as an organic inhibitor. In mango skin peel extract, characteristic testing was done using GC-MS. SEM measurement and polarization are the supporting test. Polarization measurements and SEM tests were performed at concentrations of 0 and 6 ml. The selection of these concentrations is based on the highest efficiency generated in previous studies. The results of GC-MS test on mango skin peel extract showed that mango skin peel contained Methylamine-D2 Trideuteroethene compound. This is an area of 64.34%. These compounds are considered compounds that form a thin layer on the surface of the material. A thin layer can be seen in the SEM results that have been done. The mechanism of inhibition of this corrosion process follows the Langmuir adsorption method.