The objective of this study is to suggest how to perform and what kind of methods to use for the language norms impact assessment. For this objective, this study has to analyze 4 major language norms impact assessments that had been already implemented in 2010, 2011, 2012 and 2014 on account of the Framework Act on the National Language in 2005. Before analyzing each impact assessment, we needs to prepare the analysis framework of the language norms impact assessment. We have to reconstruct the table 2.2.1 in Canter(1997, p. 48) in applying for the language norms impact assessment as choosing three general procedures and twelve types of methods in arranging them. There are several results after analyzing existing language norms impact assessment through the new table. It can be summarized like this: Those language norms impact assessments were not fulfilled completely in that they had no impact evaluation or impact prediction after carrying out impact identification. They focused on impact identification as the first stage. They did not try to utilize more various and effective methods except questionnaire and literature researching. Because they started to enforce the law without scrutinizing whole aspects of relative fields. We need to survey the valuable theoretical basis for methodology and procedure for the newly emerging language norms impact assessments.