This study is to investigate metadiscourse markers, which explicitly organize the discourse and convey a writer''s attitude to the text, in the reading parts of revised high school English textbooks and Korean scholastic aptitude tests, and to help students fully understand the functions of metadiscourse markers and use them properly. To achieve this purpose, some of the revised high school EnglishⅡ textbooks have been selected and all the texts of the Korean scholastic aptitude tests are collected. And then, all the Korean letters are removed. Next, each reading text has been analyzed through Hyland and Tse''s functional category of metadiscourse(2004), focusing mostly on how metadiscourse markers are used in reading texts. In this process, WordSmith 5.0 which is one of corpus analytical tools is used to count how many the metadiscourse markers are used in each part. The findings of the study revealed that the metadiscourse markers of Korean scholastic aptitude tests are more than those of English textbooks. Another finding concerns that the ''Hedges'' and ''Self-mentions'' items of Korean scholastic aptitude tests are more than English textbooks in the subcategory of metadiscourse markers because the former includes more argumentative texts than the latter. Especially, ''we, ''may'' and ''for example'' are very remarkable in the subcategory. Given these results, the study suggests the followings. First, more argumentative texts should be included in the English textbooks and teachers should put emphasis on metadiscourse markers. Next, although this study takes care of reading and writing parts, listening and speaking parts should also be investigated in future studies. Lastly, scholastic book authors should consider this research when writing books and setting English problems.