Abstract: Effect of homogenizing treatment on microstructure and mechanical properties of as-cast HMn58-2 alloy was investigated by means of optical microscopy(OM),scanning electron microscopy(SEM),differential scanning calorimeter(DSC), hardness test and tensile test. The results show that the ingot of HMn58-2 alloy mainly contains α andβ phase. There are a large number of dendrites with different shapes in the grain interior and at the grain boundary. The dendrites segregation and non-equilibrium phase are decreased and the mechanical properties are effectively improved for the homogenized alloy with the increasing of annealing temperature and holding time. The proper homogenizing process for the HMn58-2 alloy is heating at 810 ℃ for 6h combined with the analysis of microstructure,mechanical properties and the fracture morphology.