The purpose of this study is to design a digital library model which can provide integrated services of science information for the youth and evaluate usability. Forty domestic and foreign science websites for the youth were examined and categorized by service features. Based on the results of the examination, a science digital library was maded. And then, web log file analysis and heuristic evaluation by science experts were conducted. The results of web log file showed that users applied the most of search terms at the subject classification and words with high frequency was related to the science curriculum. In heuristic evaluation, this integrated science information system was convenient for use and expected as a valuable system which could be the science gateway for the youth by increasing the amount of contents in the future.