Abstract: The technical parameters of the chemical colouring for stainlesssteel have been obtained. The pattern of the changes of solution composition and pH in colouring process have been found out. The addition of the selected additives imporved the quality of colouring film and technical conditions. It was distinguished tentatively that the colouring film of stainless steel was a semiconductor film. After colouring and hardening, the corrsiotl resistance of stainless steel was improved.