The characters of AZ31 Magnesium Alloy are reviewed. The effects of main alloying elements on microstructures and properties, mechanical properties, grain refinement and superplasticity of AZ31 magnesium alloy are discussed. Future development directions and application areas are also introduced, noting that new forming technology magnesiumbased composites and the basis theory of AZ31 Magnesium Alloy should be future research emphases.