In the overall plan for the smart grid by State Grid Corporation， the life-cycle asset management（EAM） system is the main part of the development of state grid enterprise resource planning（ERP）. From the point of view of construction rules of the complex information system， based on the IEC 61970/61968 common information model（CIM）， the asset information model theory is described and the difference between power system resources and asset is analyzed. The disciplines and methods for the electric power information modeling are presented and used to extend to the asset information model. The asset information model includes the base model and operation model， of which the former describes equipment records while the latter covers the inspection and maintenance data. Various applications of the asset model are discussed， such as asset database design， asset classification and coding design. Moreover， the integration scheme of asset management with materials and financial management is roughly studied.