This article aims at bibliographical analysis of the <Jae Kyung chwal Yo> and historical research of Buddhism in the period of king ChungYeul. The analysis is made in the respects of: 1) physical form 2) historical aspect of the Zen Buddhism in the latter period of Koryo Dynasty 3) related persons who corresponded with Mongsan First, this books is consist of 56 records about tripitaka, biography of Mongsan, poets of Zen Buddhism, and abstracts of Buddhist books. Secondly, the new trends of Buddhism in the 13th century was influenced by Mongsan Son(contemplate school, zen). He was corresponded with some political persons and the elite class of Koryo Buddhism. Because of these meetings, LimJae Son were adopted main stream of zen Buddism in Koryo Dynasty by Mongsan and his accompanies. Thirdly, these political groups want to meet Mongsan and his teaching about zen Buddism, but he suggest three questions to the gourp instead of meeting. And he explained 10 kinds of methods to study zen Buddism comparing visited ten persons with ten pinetrees. In the Koryo Dynasty, Buddism was very inportant in history of throughts and social functions. But there had been little research on Mongsan who afford theoretical base on zen Buddism in Chosun Dynasty. On the point of the relation to Koryo and Yuan dynasty in zen Buddism. The <Bup Mun Kyung Chi> is a new and important records that afford some solutions of religious branch and trends in early periods of Chosun Dynasty.