This study was conducted to find out relationship between KSL(Korean Sign Languag e) ability and reading ability. Subjects were 19 elementary school students, 28 middle sch ool students, 26 high school students. The results are following. First, reading level of the Deaf was 1.6, 2.6, 2.7 grade level in elementary, middle, high school students respectivel y and KSL level was 43%, 67%, 74% level in elementary, middle, high school students respectively. As their grade elevating, reading and KSL ability showed significant advance ment between elementary and middle school students but not significant advanced betwee n middle and high students. Second, the higher their KSL ability was, the higher their rea ding score was, except elementary school students. Such results show that whereas KSL is the language with the structure different from written language, it works efficiently in learning reading, and as the Deaf growing up, their reading rely on KSL more and which means the need of KSL teaching systematically.