CALS is recognized as a national response to the new chapter of information society. It is essential that the standardization in Korea should be constructed compatible with not only domestic but also international standardization trend. This study aims to propose a proper direction of CALS standardization in Korea, based on the international CALS standardization movement. This paper classifies standard into five types and provides a proper direction and guidance far each standard. As a trend of CALS standard, all ten data files are converted using SGML standard far the interchangeability of data among heterogenous systems. CAD and Graphic data arc also moving toward to the STEP as their standard. In this regard, this paper discusses how to implement SGML and STEP Model. Finally, this paper proposes a method how to construct an EDI system with CALS standard and how to establish a standard authorization institute which will be responsible far the standard authorization. Furthermore, this paper also proposes the CALS Test Network (CTN) as its experimental method.