The corrosion protection of C-steel in 1 mol. L^-1 HCl solutions utilized by environmentally eco-friendly green plant extract (Polypodiophyta) was demonstrated by experimental methods as chemical approaches and electrochemical techniques. The outputs indicate that C-steel in aqueous 1 M HCl solution may be effectively prevented from corroding by using the extract solution, with effectiveness of inhibition reaching 96.2% at higher dose of 300 mg L^-1 and the higher applied temperature (55^oC).   Polypodiophyta extract, which is consistent with Langmuir isotherm, was partially chemically adsorbed on the surface of the C-steel.  On the other hand, electrochemical results showed that polypodiophyta is efficient inhibitor with efficiency reached to 91 % at 300 mg L^-1 at 25^oC. Polarization research exhibits that the extract acts as mixed hindrances. With the extract double layer capacity reduces and charge transfer resistance rises in a solution of 1 mol. L^-1 HCl. The outer part morphology of C-steel surfaces and the adsorption of hindrances on C-steel outer part can be checked by atomic force microscopy (AFM), and Fourier transform infrared spectroscopy (FTIR), the metal surface was developed a layer of adsorbed extract that shields it from acidic corrosion.