Influence of preliminary aluminizing of steel substrate on glassy coating adhesion has been investigated. Plates of type St.3 were dip coated in liquid commercial aluminium within the range of 700 to 740 deg C. Aluminized samples were then coating with a layer of crushed glass, hold up at 800-820 deg C in muffle furnace during 30 min and furnace cooled. Impact strength and linear thermal expansion coefficient were determined. It is shown that aluminizing can increase impact strength 1.5 times for glassy coatings. Linear expansion coefficient is noted to be in agreement with thermal expansion of steel but not aluminium.