The aim of this study is to analyze biographical records and Meritorious Certification of Jeong In-Kyung. The analysis is made in the respects of : 1) Bibliographical analysis of the (SeoSan Jeongshi GaSeung) 2) Biographical study of Jeong In-Kyung 3) Historical and Political background in the period of king ChungYeul The summary of this study is as follows: 1. The <SeoSan JeongShi GaSeung) is consist of biographical records of Jeong In-Kyung and his father. This book was published by wooden movable type printing at 1819. 2. The JeongAn is primary source to give an official order and nomination. Through these records, we can draw the genealogical charts and his personal history. 3. The Meritorious Certification refers to an authorized document which was confered to subjects that had been devoted themselves with royalty for the king ChungYeul. 4. In the analysis of main body of the certification, this thesis research 1) the reason of political accident at the year Gisa 2) the instances of merits by grade of awardees 3) the awards and privilege according to merit grade 4) the organization in partial charge of awarding 5) the staff and their titles of the office of meritorious subject affairs 6) additional notes of the awarding that were originated by Yuan Dynasty 5. This thesis confirms that these biographical records and the certification are of high value from the viewpoint of primary historical materials concerning the personnel administrations on latter periods of Koryo Dynasty, and also a linguistic material of Idu writing system was used.