Collection of Gangseo poems, whose poets began to appear during the reign of King Seongjong, published in the end of Goryeo Dynasty and in the beginning of Joseon Dynasty, Gangseo Poetry Group said that they specified how to write a good poem and should learn it thoroughly. As they experienced the political difficulties, they gradually turned into resignation and comfort. People had good feelings toward the poems reflected their spirit. The poetry group which was called Haedong Gang Seo Poetry Group included Bak Eun, Yi Haeng, Bak Sang, Jeong Sa-yong, No Su-shin and Hwang Jeong-uk, was appeared during the reign of King Seong-jong and Seon-jo. No Su-shin who was a member of Haedong Gang Seo Poetry Group embodied Hwang Jeong-gyeon’s “Yi Sok Wi A” theory as the style of Yi Dynasty. Writing materials So Jae burst into strong feelings using alteration of Yo Chae(拗體). He realized its essence in the middle of learning Du Bo who was good at Yo Chae. People blamed him because he used vulgarism, proverb, place name, name, sexagenary cycle, date in his poems, but some critics such as Heo Gyun, Hong Man-jong and so on praised him. That’s why he had showed the stage of “Yi Sok Wi A(The ordinary things become beautiful)”. As he arranged the real and the false letters well, it made its meanings strong through the inversion in the sentences. It was said that he with Bak Eun and Yi Haeng took pride in the arrangement of the real letters. He also created the new meanings through using the precedent(典故), combined, borrowed and altered the letters partially. He used them to broaden the boundary of its meanings. When he arranged the sentences, he made the appropriate sentences using introduction, development, turn, and conclusion, four steps in composition. No Su-shin had lived in exile for 22years because of Ulsasahwa[乙巳士禍] three years after he entered the government. He was a genius and study very hard when he was young, so many people aspired him to be a great man. Although his exile was the ordeal for him because of the political cession, he read the Du BO and the Analects of Confucius more than two thousand times and mastered them. He established his theory which challenged the Neo-Confucianism and he obtained good results in his own way. He wrote papers such as Gon Ji Gi Bal[困知記拔], Suk Heung Ya Mae Jam, Jip Jung Seol, Yin Shim Do Shim Byeon[人心道心辨] and etc. He argued with Yi Hwang, Gi Dae-seung, Kim In-hu, Yi Hang several times. His philosophy included Na Jeong-am’s theory different from Ju Ja Hak[朱子學]. That’s why he took criticism from the civil servants who called his theory Zen Learning and herecy. He wrote 1023 out of 1449 works during his exile. Their theme was the affection and sorrow of the part, missing the family, comfort from the friendship, overcoming the despertion, passion for the scholarship, being loyal toward the king, loving people and diplomacy. He was good at 5-eun[五言] contrasted with Je Sa-eun proficient in 7-eun[七言]. So Jae influenced in the field of poem literature history and the realm of ideas. He embodied Du Bo as the member of Hae Dong Gang Seo Poetry Group in the style of Yi Dynasty and handed down the theory of the group to Choe Gyeong-chang, Baek Kwang-hun, Yi Dal.