Abstract: The role of cetyl pyridine bromide in the corrosion inhibition of aluminium in hydrochloric acid has been investigated by weight loss method. The experimental data have been treated with adsorption theory and Sekine method. The adsorption heat has been calculated. It is found that adsorption of cetyl pyridine bromide from hydrochloric acid solution on aluminium surface obeys basically Langmuir′s isotherm, so the adsorption on aluminium surface was believed to be an important reason of corrosion inhibition. The corrosion inhibition efficiency increases with raising temperature. Relationship between adsorption and corrosion inhibition has been discussed according to the experimental results.