During the process of power system standardization

the problem caused by the lack of united and standard data structure is becoming more remarkable.Based on the studies of power system model

the relay protection data exchange standard of power system is improved and implemented

a XML document of structured format to contain relay protection data is designed

and a system of data exchange is put forward.By utilizing XML’s feature of independence and separation between the content and representation of a file

the data could be exchanged effectively between different applications and systems.And it could be described in different formats according to different demands of the user.In addition

some methods to manipulate the XML document by C# programming language are provided.