The results of researching Jang`s use of herb remedies through his book 『Uihakchungjungchamseorok(醫學衷中參西錄)』 are as follows. 1. Jang Seoksun`s medicine is based on 『Hwangjenaegyeong(黃帝內經)』, 『Sanghanron(傷寒論)』, 『Sinnongbonchogyeong(神農本草經)』. And through constant study he brought to perfection his own unique medical theory. 2. He introduced Western medicine, and united it with traditional Chinese medicine. He perfected the Chinese-Western medical theory, by Chungjungchamseo(衷中參西) which means ``roots in traditional Chinese medicine, reference in Western medicine``. 3. He thought Onbyeong(溫病) was not an independent category of disease, but included it into the category of Sanghan(傷寒). So he used modified prescription of 『Sanghanron(傷寒論)』 to treat Onbyeong(溫病). 4. He expanded the category of remedy uses by using various compounds, such as minerals and animal compounds. He has also developed substitute remedies.