The purpose of this study are to analysis the factors of stduy skills and to find tool of differences among six study skills in terms of three achievement levels of Elementary students. The six study skills in the study are Self-management skills, Study motivation, Information Processing, Participating in class, Reading and Writing skills and Test-wiseness skills. And the three achievement levels of students are normal achiever, underachiever and overachiever. The study seeks to answer the following problems. 1) Are there some differences in study skills according to the grades? 2) Are there some differences in study skills according to the sex? 3) Are there some differences in study skills according to the academiclevels? The subjects of this study are 340 Elementary school students in Pusan. And they are divided into three groups: the normal achiever group, the under achiever group and the overachiever group. The statistical methods applied in this study are Oneway ANOVA, Duncan Post test, t-test. Major findings were as follows; 1) There sre no differences in each skills according to the grades. 2) There sre differences in each skills according to the sex. That is, the female use Self-management study skills and Test-wiseness skills than male. 3) There sre differences in each skills according to the levels. That is, the overachiever use participating in class and Reading and Writing skill than normal achiever. And the normal achiever use six study skills than under achiever. It is necessary to encourage students to use study skills more.