Abstract: The microstructure developing of 60Si₂Mn semisolid slurry was investigated experimentally with self-made high melting point semisolid apparatus. The results show that the as-received microstructure of semisolid samples presents globular crystals evenly distributed in the liquid phase. Stirring way and stirring power and time have evident effect on the solidifying pattern of the primary phase. The as-received prior microstructure which is stirred in the isothermal way evolve fully finer and rounder with the increase of stirring power and time. The morphology of 60Si₂Mn semisolid samples is major factors that affect the shear thinning behavior.