The inhibitor is a substance added in small amounts which aims to inhibit the corrosion rate. Organic inhibitors are environmentally friendly inhibitors. Currently organic inhibitors are studied by many researchers. Natural ingredients are the raw material in research on organic inhibitors. In this research, polarization testing and FTIR have been done. Papaya leaves as a raw material of organic inhibitors are used, while the corrosive medium is a 1 M HCl solution. Based on the polarization test, the corrosion rate absence inhibitor was 21.43 mm/year. This corrosion rate decreased to 0.4 mm/year. Highest efficiency generated by 97%. This efficiency occurs in the presence of 2.5 ml concentration of corrosion solution. In the polarization testing showed that the inhibitory mechanism that occurs cathodic dominant. This is supported by FTIR test results. The results of this test indicate the absence of the same functional group between the extract and the specimen with the inhibitor. The inhibitory mechanism of cathodic inhibitors is that the inhibitor reacts with the corrosion solution so as to decrease the rate of corrosion that occurs.