The personal praying sentence in personal praying scripts of Koryo Dynasty should be very important source for study of Koryo buddhism's history as well as historics, bibliographics and art historics. Especially it would be good source for study of official position in Koryo Dynasty because in the personal praying scripts the prayers expressed their own official position when compared to the official positions presented in Bekguanji(all officer's magazine) in Koryosa(history of Koryo Dynasty). As the characteristic of script is presented in the contents of personal praying sentence, it would be remarkable source for study on the history of buddhism's thought. Through the personal praying sentence it is possible to make clear the hopes of donor and high monks who were the key members for writing praying script. Also study on the personal praying sentences in Koryo scripts would be helpful for understanding the profile of society of Koryo Dynasty.