In this research, Effect of the annealing heat treatment on the coating microstructure and formability of the hot dip galvanized sheet was evaluated. For this aim, some samples of galvanized sheet with same production situation, mechanical properties and coating, in temperature range of 500-580 ?C and for 10-180 seconds heat treated. After heat treatment, the samples were cooled in the water and dried quickly. In order to evaluating of microstructure and coating layers, the optical and scanning electron microscopes were used before and after heat treatment. To specify of layers chemical analysis were also used the energy dispersive spectroscopy (EDS) microanalysis and the phases in the coating was recognized by x-ray diffraction. Uniaxial tensile test and drawing of forming limit diagrams (FLD) were used for evaluating the formability. Circleshape patterns were also exerted on the galvanized and heat treated sheets with different widths by electrochemical etching procedure and in the lubricant state deformed up to fracture by hemispherical punch with 60 mm diameter. In order to measuring of strains used miler ruler and fracture cross section of deformed samples were studied by scanning electron microscope. Evaluation conclusions shows that surface appearance quality change by temperature and time of heat treatment, so that surface appearance change from silvery and bright to gray and dull by increasing of temperature and time. Furthermore, Conclusions of the formability evaluation shows that growing of the Iron-Zinc brittle intermetallic layers and complete removing of Eta phase in heat treatment decrease the level of forming limit diagrams. Also heat treatment in the higher temperatures and lower time improves the coating formability behavior.