The application of magnesium alloy die castings is limited by variations in the mechanical properties in high pressure die casting components. This can be ascribed to a heterogeneous distribution of microstructure in high pressure die casting. In this work, the through-thickness distribution of the microstructure featuresof HPDC AM60 alloy and their effects on the strain heterogeneity and the microhardness variation were carefully investigated.In the as-cast sample, heterogeneous deformation can be observed at strain of 3% using digital image correlation (DIC) method. The strain in the skin regions is homogeneous, whereas significant strain heterogeneity was presented in the core. After T4 treatment, remarkable strain heterogeneity can still be observed, indicating that β-phase does not have profound effect on deformation heterogeneity. Strain localized at the interdendritic regions of ESCs and the vicinity of grain boundaries in fine-grained regions, where porosity occurred due to shrinkage during solidification.