This thesis describes, analyzes and study primarily 13 se lected MSS of the ancients manuscripts, which a re found in Dabra \-layq St. 3stiphanos Abuna lyyasus Mo'a, monastery. The historical and philological significance of thc manuscripts is investigated in terms of cataloging. The cataloguing has been made in order to study the authenticity of the MSS, to list out unknown and ancient MSS using the scientific method and to give an ext ensive comment on the physical and substantial nature MSS. The research enclose MSS which a re not previously cataloged by others scholars. I t is made through critical and careful id entification by the help of observing a lready publi shed materials , microfilms, observing inventory records of the monastery's Q'esa-Gabaz (Treasurer). The study is significant for further studies. The pnmary materials the researcher uses are digital photographs of 13 MSS which are found in Dabra I;-l ayq. Where as other sources like interviews, In - depth investigation of the collections of (Ethiopian manuscripts microfilm Library and Hill Monastic Microfilm Library which are catalogues of numerous Ethiopian manuscripts available in IES and National Library). The research answers questions related to the major importance and significance of cataloguing man u scripts with reference to Dabra \-layq St. 3st;iphanos Abuna Iyyasus Mo'a, monastery. In this regard it is very useful to perform professional cataloging in many manuscript collection of Ethiopian Church.