This paper introduced the grounding metal materials commonly used in the domestic power transformer field, and compared the properties of these metal materials. The connection technique of these materials was also introduced including galvanized steel, stainless steel, copper, copper clad steel and so on. The properties of the connection technique were compared, such as the melting point of joint, process property, service property, economy. The results show that the grounding system construction should be chose in accordance with the actual demand, according to the characteristics of material and connection technique.