This paper analyzes the methods commonly used to describe the  testing information in graphical automatic test systems,introduces briefly the architecture of the graphlabel based automatic test platform. Then,it defines several languages by the XML schema to describe the testing design,including hardware environment design,flowchart of the testing program,as well as the input/output data of a test. It defines a graph marked language for describing the  interface information of the test,and testing the marked language for describing parameters,programs and  data. In this way the design of a  test and the testing program are loosely related. It can exchange data with other systems and can be generalized and updated easily.