In order to understand the effect of microstructure on mechanical properties of TIG welded AZ31 Mg alloy sheets, EBSD analysis and microhardness measurements were carried out at the three regions (Fusion Zone, Heat Affected Zone, Base Materials). EBSD analysis revealed the heterogeneous distribution of grain size and microtexture in the three regions. Microhardness measurement also provided that how grain size and micro texture contribute to the microhardness distribution in the three regions.