Yu Gil Jun thought that his `Seagy` theory completed during his studying in Japan and America, could helf accomplish social enlightment and strengthen the power of Chosun, the name of the most recent kingdom in Korea`s old times. So he tried to reform his country`s education necessary to realize his `Seagy` theory. His education-reforming theory basically differs from the traditional education system at those times, usually teaching Confucianism. The old system, the final goal of which was to pass the higher civil service exam, had a curriculum to justify its state-rank order. The purpose of his theory, however, was to make a new education system for a new rich country with a strong modernized army. The characteristics of Yu Gil Jun`s education reforms theory, for which especially analized his book, `sougyonmun`s` (the Essay on Western Country), are as follows; 1) to build an independent modern country, leveling up its people, enriching its government, and enlightening its society. 2) to divide education into two parts, daily education and academic education. The former teaches knowledges and skills necessary for life. The latter seeks to acquire truths of the nature. 3) to improve the quality of education, using many practical and adequate methods dependant upon how far students psychologically develop and accomplish their knowledges.