Steel is the most important construction material in the building industry. To reduce corrosion zinc coatings are applied. The most important production process for these coatings is the continuous hot-dip galvanizing process. A rather new development for metallic steel coatings is an alloy based an the Zn-Al-Mg-system. These alloys show a better corrosion performance than the classic zinc layers. However, they are more brittle compared to pure zinc-coatings and at deformations during subsequent processing a different development formation of microcracks can occur. The aim of this work is to evaluate the microcracking behaviour of various Zn-Al-Mg-coatings. The coating-process was carried out by a hot dip galvanizing simulator. A Stepwise stretching of the samples and the evaluation of the microcracks took place in order to track the formation and propagation of the microcracks. For investigations, on the microstructure a scanning electron microscope was used. The number of microcracks increased with higher contents of magnesium and decreased with the aluminium content. A higher layer thickness affected a development of more microcracks. The hardness of the layer grew with increasing aluminium and magnesium content.