The present investigation aims to synthesize and explore the influence of pyridine and pyran derivativeson the API X-65 steel corrosion in a 6 M H2SO4 solution. The compound was examined at differentconcentrations to optimized the best concentration for the corrosion inhibition effect, weight lossmeasurements, potentiodynamic polarization measurement (PDP), electrochemical impedance spectroscopy(EIS), scanning electron microscopy (SEM) and theoretical methods were used to evaluating theinhibition efficiency. The obtained adsorption data achieved the model of Langmuir isotherm. Thepyridine derivatives showed higher inhibition than pyran derivatives. The PDP tests proposed thatpyridine and pyran derivatives are mixed-type inhibitors. The EIS parameters demonstrate that thedouble-layer capacitance (Cdl) decreases with the increase of inhibitor concentration, which implies areduces dielectric constant. It was observed from experimental data that the inhibition efficiency reached92.7%, 89.1, 94.7, and 85.2% for concentration 2.66 10 3M of I, II, III and IV, respectively indicating theinhibition order is III > I > II > IV. The parameters derived from the theoretical quantum chemicalcalculations were found adequately correlated with the obtained experimental results.