In order to learn more about the causes and state of preservation of cremation ironware having special shapes, scanning electron microscopy, stereo microscopy, Raman spectroscopy and a residual chlorine meter were used to analyze archaeological ironware excavated from the Yunfeng reservoir of Liangmin, Jilin Province,and its environment. The results show that the special shapes formed during the fire cremation. The iron in the ironware body turned to hematite and became more stable. However, it also became harder and brittle after heating, and its mechanical strength weakened. The high temperature not only changed the mechanical properties of the ironware, but also added a greyish blueblack color effect to its surface. The uniform porous microstructure made the ironware surface dry and rough. This research is valuable for the preservation of refired ironware and for the funeral customs study.