N1, N2-bis [1-(pyridin-2-yl)ethylidene]oxalohydrazide inhibitor (NOL) were synthesized and evaluated as cor-rosion inhibitors for stainless steel 304 L (SS304L) in one molar HCl. The adsorption properties of the synthe-sized NOL were determined by experimental and theoretical methods in an acid environment. With the aid of chemical methods such as mass loss method (ML), DC potentiodynamic polarization (PP), and AC impedance (EIS) tests. Outcome data obtained from these methods displayed that with increasing the concentration of these substances their inhibition efficiency (%IE) increased and reached 95.7 %. The presence of NOL reduces the capacity of the double layer and improves the charge transfer resistance in a solution of 1 M hydrochloric acid. NOL is a mixed-type inhibitor, conferring to the polarization curves. The attained data indicated that NOL was chemically adsorbed onto the SS304L surface in accordance with the Temkin isotherm. The surface protection examination was carried out using scanning electron microscopy and the formation of the complex on the surface was approved using Fourier Transfer Infrared Spectroscopy (FTIR). Also, the quantum chemical para-meters of NOL were computed and discussed. The results of several methods are in agreement with each other.