Abstract: Substation automation system of countryside level plays an important role in control and automation of power system. IEC61850 is an international communication standard of substation automation system, It represents the future directions of developments for substation automation. This paper analyzes the main technical features of IEC 61850——network leveling, unified object-oriented modeling, data object self-description and abstract communication service mapping etc in detail. The design and realization of IEC 61850 standard are proposed in substation automation system of countryside level. The modeling approach and the data models of IED are discussed.