Corrosion is a natural process that converts carbon steel into a more chemically stable form such as oxide. In general corrosion is unavoidable but the corrosion rate can be slowed down. The process of corrosion is the gradual destruction of materials on metals by chemical or electrochemical reactions with its environment. Various ways are used to harm the corrosion damage of metal objects exposed by weather, brine, acids or the environment. But in practice used environmentally unfriendly materials as corrosion prevention material so harmful to the environment. In this study, it aims to determine the effect of eichhornia crasipes extract as a environment friendly inhibitor of API 5L Grade B Steel in a 1 M acid HCL Solution. Efficiency Inhibitor can be known to use electrochemical impedance spectroscopy and potentiodynamic polarization. The test result potentiodynamic polarization of organic inhibitors gained an efficiency of 96.73% with a corrosion rate of 1.0954mm/year at 400ppm Concentration. At electrochemical impedance spectroscopy test, acquired efficiencies 92.26204% with corrosion rate 1.0434mm/year at 400ppm Concentration. Test conducted using the concentration of Eichhornia crasipes extract of 400ppm. The results of this study showed that the inhibitors of organic Eichornia crasipes extract efficiently reduce the corrosion rate of API 5L Grade B steel in acid circled.