The purpose of the study is to analyze the Activities which was high Buddhist priests in The late Koryo' s and early Cho-sun Dynasty with masters of Yugi' ca' ra(?伽) sect Buddhism. Meanwhile the lack of historical documents on Masters makes it difficult for us to study on their religeous thought as well as re1igeius actvities. The impotantce of Sujongsa(水精社) lies also it: s influence on latter Kyolsa movemenr(結社運動) which flourished during the Millitary Goverment Period and shared some of it: s basic features. Budddhism under the Dominaion of the Yu an(元) Dynasty, following reqests by the Mongol court, many Buddhist monks were sent to the capital Tadu(大都) in order to copy entire sets the sutras, in which Koryo dynasty priests were particularly well versed. Taking this opportunity, during the period of Mongol influnce as many as two Yuga' ca fa' s priests became National Preceptors(國尊) there by controlling the religion affairs of the whole country. For example the high priest of Yugi ci. ra appointed Hyeyoung(惠永), Meesu(彌授) and acted HyewonGftIll), Chonglim<**) etc. Especially Meesu became Camhoeisata master who accepts pentice and gives Buddhist Cammandments(憐悔府師) and appointed head priest and managed temples, Chonglim acted Anyang temple(安養寺) in the capital Hanseong(漢城) s vicinity and keeped company with New Confucian(新進士類), who were in opposite situation against establishment of new dynasty. Finally Yugi ci. ra priests leaded to Buddhism for 20 years off and on 14th century but became weakened in the late Koryo' s and early Cho-sun dynasty.