Abstract: A method of preventing corrosion of metals using bis-functional polysulfur silanes. The method includes providing a metal surface, and applying a treatment solution onto the metal surface. The treatment solution includes at least one hydrolyzed bis-functional polysulfur silane of the formula: ##STR1## wherein each R is an alkyl or an acetyl group, and Z is either --S.sub.x or --Q--S.sub.x --Q--, wherein each Q is an aliphatic or aromatic group, and x is an integer of from 2 to 9. A treatment solution and metal surface having improved corrosion resistance are also provided.