It is necessary to have an interest on the change of literacy environment which has been derived from the development of digital technology in order to discuss the 21C Korean competence. The interest on these kinds of change are well shown in the reading assessment in OECD PISA. The aim of this study is to investigate the reading literacy which are required to the 21C people based on the analysis of the theory, framework and items of PISA 2009 reading assessment. First, existing arguments which have studied the change of literacy environment were examined. There are many kinds of existing arguments defined new era as new media age and they emphasize the importance of new literacy concept. Multi literacy and multi-modal literacy are typical examples of these arguments. Arising arguments which emphasize the new literacy have a tendency on the critical literacy study on the focus of social function of literacy. On the contrary, other argumentations define these change as the aspect of the late age of print and insist integrative approach of old literacy and new literacy. Reading literacy in PISA covers both perspective. Especially, PISA DRA reveals that critical thinking is the key factor on digital literacy. Hypertext reading that is comprised of text processing and navigation is also regarded as key factor on digital literacy. Therefore, the change in literacy environment doesn`t mean the variation of core meaning of required reading literacy. It is strongly required to develop the ability of making meaning and critical literacy for text to fulfill the Korean competence for 21C. It is just needed to get familiar with the diverse channel that classify the meaning of text in considering of the formal characteristics of digital text.