Abstract : The azo dyes (S1, S3, S4) were prepared by diazotization and pairing reaction with 1-naphthol. The prepared azo dyes were diagnosed by FT-IR, 1H-NMR spectroscopy and mass spectrometry. In addition, dyes were studied as corrosion inhibitors to achieve the corrosion inhibition of carbon steel surfaces at various concentrations and different temperatures in (1M) HCl. The results were obtained by using potentiodynamic polarization measurements. It was found that (S3) gave the higher inhibition efficiency (%IE = 87%) at 25°C, 5×10-2M. Adsorption isotherms were studied and followed Langmaier's law for their fit to experimental data. Thermodynamic measurements were determined (activation energies(Ea), enthalpy (ΔH*), entropy (ΔS*), and free energy (ΔG*)). The adsorption equilibrium constant (Kads) had a close correlation coefficient (R2), which was close to the value of one.