In the last years the considerable increase of the use of magnesium alloys is noted, especially in the automotive industry. The driver of this increase is the possibility of the weight reduction of car for decreasing of fuel consumption and next the achieve of economic and ecological effects. Together with the increase of use of magnesium alloys the development of investigations of new production technologies of magnesium itself and its alloys - which will have, among others, better corrosion resistance - is noted. Regarding on, among others, the weak anticorrosive properties, the preparation of surface of magnesium alloys, treated as a final processing, or as the processing previous further technologies, especially coatings, state the particularly important problem. Turn attention onto fact, that many modern technologies - recommended to chemical processing of magnesium alloys, were successfully tried out on aluminium alloys In the paper the different possibilities of magnesium application in automotive as well as chemical surface treatment of magnesium were described.