The corrosion inhibition of C38 steel in molar hydrochloric acid solution with different concentrations by three newly synthesized imidazopyridine derivatives namely: was studied using gravimetric, potentiodynamic polarization (PP) and electrochemical impedance spectroscopy (EIS) measurements. All compounds have shown good inhibition efficiency (IE %) in acidic solution range 86.5-92.5% for 10-3M at 298K, this efficiency decreased with decreasing the inhibitors concentration and also decreases with increasing temperature. Potentiodynamic polarization studies suggested that the imidazopyridine derivatives mixed-type inhibitors and impedance measurements showed that the double layer capacitance (Cd) increased with rise concentration of the studied inhibitors. The compounds were adsorbed according to the Langmuir isotherm and the inhibition influenced by ô hemis- and chemi-sorption. Some thermodynamic functions of adsorption and dissolution process were calculated and discussed.