The present invention provides a method of coating aluminum and aluminum alloy substrates by which not only a corrosion resistance comparable or even superior to that afforded by chromate treatment can be imparted but also the adhesion to the coating film can be improved, while the luster of aluminum is fully retained, notwithstanding the use of a chromium-free treating solution, as well as a coated article with the coated surface according to the above method having a metallic luster. The present invention provides a method of coating aluminum and aluminum alloy substrates which comprises treating an aluminum or aluminum alloy substrate with an acidic solution containing sulfuric acid and 0.2 to 0.4 g/L of a ferric ion and having a pH value of 0.6 to 2.0, subjecting the same to chemical conversion treatment with an acidic coat-forming agent containing 0.01 to 0.125 g/L of a zirconium or titanium ion, 0.01 to 1.0 g/L of a phosphate ion, and 0.01 to 0.5 g/L of a fluoride ion and having a pH value of 1.5 to 4.0, followed by coating.