This study was to compare the description of content types(content forms) and media types of RDA and ISBD in order to revise GMD of KCR4. Test and survey were conducted as the research methods for comparing content types and media types description of RDA and ISBD. As a result, RDA content types description is better than ISBD in aspects of uniformity and correct rates. Especially, detailed list of content types in RDA could make the resources to be expressed completely, but content forms with adding the content qualification in ISBD could make the resource to be expressed with many errors. Therefore, there were some considerations to describe content types. First, content types terms in RDA need to be specified more. Second, some detailed rules need to be regulated on the combination of content qualification of ISBD. Third, the mapping tables between RDA content types and ISBD content forms need to be revised. Fourth, RDA content types list will be more applicable in KCR4 based on the uniformity and correct rates in the test. This study will contribute to analyze and suggest RDA and ISBD terms list of content types and media types for KCR4.