Abstract: A cleaning composition for electrolytically cleaning cold-rolled steelwork includes sodium or potassium hydroxide, sodium or potassium orthosilicate and a combination of non-ionic surface-active agents; said non-ionic surface active agent includes a major amount of lauryl polyethylene glycol ether with 10 moles of average ethylene oxide, and a minor amount of nonyl phenyl polyethylene glycol ether with 1 mole of average ethylene oxide. By virtue of adding two non-ionic surface active agents in such an amount ratio, an excellent defoaming and cleaning effect can be obtained. Inclusion of hexamethylenetetramine in the cleaning composition can inhibit the deposition of ferric oxide and silicone oxide during electrocleaning which normally gives rise to the problem of light fault.