This thesis describes, analyzes and study primarily 13 se lected MSS ofrnthe ancients manuscripts, which a re found in Dabra -layq St. 3stiphanosrnAbuna lyyasus Mo'a, monastery. The historical and philologicalrnsignificance of thc manuscripts is investigated in terms of cataloging.rnThe cataloguing has been made in order to study the authenticity of thernMSS, to list out unknown and ancient MSS using the scientific methodrnand to give an ext ensive comment on the physical and substantial naturernMSS. The research enclose MSS which a re not previously cataloged byrnothers scholars. I t is made through critical and careful id entification byrnthe help of observing a lready publi shed materials , microfilms, observingrninventory records of the monastery's Q'esa-Gabaz (Treasurer).rnThe study is significant for further studies. The pnmary materials thernresearcher uses are digital photographs of 13 MSS which are found inrnDabra I;-l ayq. Where as other sources like interviews, In - depthrninvestigation of the collections of (Ethiopian manuscripts microfilmrnLibrary and Hill Monastic Microfilm Library which are catalogues ofrnnumerous Ethiopian manuscripts available in IES and National Library).rnThe research answers questions related to the major importance andrnsignificance of cataloguing man u scripts with reference to Dabra -layq St.rn3st;iphanos Abuna Iyyasus Mo'a, monastery. In this regard it is veryrnuseful to perform professional cataloging in many manuscript collectionrnof Ethiopian Church.