The trend of collecting and appreciating antique and beautiful artifacts was prevalent amongst the literary men of Seoul-Gyeonggi areas in the 18th century Joseon, and this resulted in the appearance of a lot of individual collectors, They included a wide range of gentlemen from noble families to middle class families who shared a consciousness of literati, Many studies have been conducted about it as they were influential to their contemporary painters as patrons. However, there is no explanation as to how they patronized the painters. This study traces and presents the collector' s painting collections and examines their collecting methods in order to investigate the relationship between collectors and painters. Based upon it, this paper also examines how the 'great collectors of the 18th century' namely Yi Byeong-yeon (李秉淵), Yi Ha-gon (李夏坤), Kim Gwang-su (金光遂), and Kim Gwang-guk (金光國) patronized the contemporary painters through their collecting activities. This will further the investigation of characters of the collectors as patrons and see their influence on painters and their works in the 18th century in details. Collectors from the gentry literary men had some aspects in common: they were members of noble families which had established the physical grounds for political, economical and social development since Seonjo (宣祖)' s reign: landowners whose ancestors held posts of high ranking central government officials in the 17th century: elite literary men who were brought up in the environment where they had easier access to the products of Chinese culture. Many of them, however. pursued the recluse life style and gave up successful official careers. They enthusiastically practiced collecting, appreciating and criticizing beautiful artifacts in private sectors such as sarangbang, gentlemen's studies and poetry gatherings. It was considered the ideal path of a literati' s life and was regarded as the elegant way towards valuable friendships. The middle class literary men who took part in the above circles shared the taste of the gentry literary men and eventually identified themselves as the successors of Joseon literati culture. This consequently produced collectors from the class. Kim Gwang-guk was a medical official from the family who practiced medicine for generations and became an outstanding collector whose wealth was accumulated through his career as well as trade activities in China. The painting collections of the literati collectors in the 18th century mostly consisted of old and modem paintings from Korea and China. However, Japanese and Western paintings were sometimes found as well (see table 1-4). Literati men and painters observed the ample collection of Chinese paintings from Tang to Qing dynasties, and they were attracted to the works of the great masters of Southern School such as Tung Yuan (董源), Mi Fu (米?), Huang Kung-wang (黃公望), Ni Tsan (倪瓚), Shen Chou (沈周) , Wen Cheng-ming (文徵明), and Tung Ch' i-ch' ang (董其昌). It was also possible to enjoy the works of Nanking school, Anhui school. Orthodox school, and Individualist school in the late Ming and early Qing. It is believed that these Chinese paintings played a significant role in the painters' understanding of Chinese literary painting style along with that of all sorts of wood block prints. This at the same time initiated the painters to deal with various subject matter than they did before. On the other hand, Kim Gwang-guk mainly collected Joseon paintings and compiled them into a set of album, Seoknonghwawon (石農畵苑). Although the album has been divided and scattered, it still maintains the systematic form of the three perfections-prosaic writing, calligraphy and painting. This unique, completed form of the album which he intended for suggests that he was a genuine collector and an enlightened conservationist. Such paintings came into the hands of collectors through either inheritance in the family or purchase or commission in the 18th century. First of all, the method of handing down paintings through the family was much encouraged as it was believed to commemorate one's ancestors and to transmit the family custom. It furthermore justified the act of conserving and enjoying paintings, overcoming the limit of discourse of Wanmulsangji (玩物喪志) that had repressed the activities. It is known that commissions to copy and conserve them encouraged the production of the works of the contemporaries. Secondly, in the 18th century Joseon society, paintings that had left the artist' s hand and came into the possession of others were treated and traded as a commodity just like Chinese paintings were. It was a sort of luxury consumption. They were traded either in forms of currency. and were bartered with paintings or with other things such as food, wine, silk, paper, etc. This fact implies that social structures of that period were built to collect paintings with one' s wealth as well as with the power from political status. Lastly, through analysis of examples of commissioned works that boosted the production of the contemporary painters, it was revealed that some painters complied with their commission by getting paid what is suitable for their works. They also traded with their clients through either currency and bartered with paintings or with other things. This evidence shows us that there were professional painters in the 18th century of Joseon, who went beyond the established categories in the history of painting in the late Joseon period, known as court painters versus amateur literati painters. It is important that the commissions of collectors from gentry literati, Yi Byeong-yeon, Yi Ha-gen, and Kim Gwang-su, boosted the production of contemporary painters in the early and mid-18th century. They played the most influential role in the production of topographical landscape paintings and literati genre paintings by commissioning great painters, notably Jeong Seen, Jo Yeong-seok, and Sim Sa-jeong. In particular, Yi Byeong-yeon introduced Jeong Seen to many literary men and contributed to building a firm stratum of clients for him as well as insuring his social growth as an artist by arranging commissions between them. Additionally, their collections were opened to the painters and eventually contributed to the development of their paintings. It is presumed that Jeong Seen' s early style with delicate brushwork in ink and water color seen in his Ssangdojeongdo (fig. 10) and Gyeonggyomyeongseungcheop (fig. 5-7) were acquired through observing Yi Byeong-yeon' s collection. The poetic scenes adding a tinge of color (fig. 8) and the method of depicting details seen in the river landscape paintings of Jeong Seon after 1730s (fig. 9, 6, 7) are believed to reflect Yi Ha-gen' s taste and result from viewing his collections. Sim Sa-jeong' s Gangnamchundo (fig. 11) was an imitation of a Chinese work in his collection. Yi In-sang's Iinmuldo (fig. 1) and Sim Sa-jeong' s pursuit of reproducing old paintings and producing his works through creative copying were influenced by Kim Cwang-su s taste and collection, who understood the lineage of Southern School style. Kim Gwang-guk continued to collect paintings mainly through purchasing. Most of his painting collection in Seoknoughwawon was comprised of the production of Joseon artists, however. it was not closely connected to the contemporaries. Instead it provides us with much useful information about the painters and his critiques on each works by his prosaic writing. Kim Gwang-guk basically persisted on the viewpoints of literati's on appreciating paintings, and emphasized the importance of practicing the style of Southern School. It could be due to his self-consciousness trying to stand above his innate social status through the activities. For this reason, he was able to become a critic who stood up for the court and the middle class painters in the late 18th century. He elevated them to the level of Chinese great masters. and also successfully helped with the debut of minor and unknown artists to the stage of history. He is believed to be the true patron of his contemporaries in this respect. By and large. it is important that the desire of collectors to gather, appreciate and preserve paintings was practiced among the Joseon literati's society in the 18th century, and this consequently gave opportunities and motives to the contemporary painters to produce diverse works. Besides, the collections were viewed by them and enriched their visual experiences that later brought to produce lots of brilliant paintings. The remarkable development of painting in the late Joseon period was possible for many reasons. However. most importantly. the contribution of collectors and painting lovers in building the environment where the painters were commissioned to produce what clients desired. were able to view the collections that broaden their knowledge, and were sufficiently understood and criticized for their works should not be neglected.