3-amino-2-phenylimidazo[1,2-a]pyridine (P3) newly synthesised was tested as corrosion inhibitor of C38 steel in 1M HCl using weight loss method, potentiodynamic polarisation and electrochemical impedance spectroscopy (EIS) measurements. Gravimetric essays indicate that P3 inhibits the corrosion of steel. The effect is more pronounced with increasing of P3 concentration. The inhibition efficiency attains 92.8 % at the 10-3M. P3 affects both cathodic and anodic current and then limits H+ reduction and iron dissolution. P3 may be classified as a mixed inhibitor. EIS diagrams show that adsorption of P3 increases the transfer resistance and decrease the capacitance of interface metal/solution. Langmuir isotherm is the best fitted adsorption one to describe P3 action on steel surface. The negative values of DG° ads indicate the spontaneous adsorption of the inhibitor on steel surface. Both kinetic parameters (activation energy, pre-exponential factor, enthalpy of activation and entropy of activation) were calculated and discussed.