The type, shape and distribution of carbide take directly effect on the mechanical properties of high chromium castings. Vanadium is able to stabilize the structure of carbide in high chromium cast iron, meanwhile the hardness of carbide containing vanadium can reaches about 2800HV. In some cases, vanadium can also refine the microstructure. Rare-earth is able to change the shape of carbide in cast iron, refine the grain size of ferrite and improve the mechanical properties of castings. In this experiment, intention of adding vanadium and rare-earth is modification of mechanical properties with the proper heat treatment technology. With the help of SEM, the characteristics of carbide, such as shape, distribution and quantity can be observed and mechanical properties have been improved for better wear-resistance.