The study aims at defining the Cataloging in publishing (CIP) and the local institutions in the country which prepare its data and matching these data with the international standards and rules to assure their validity, completeness, quality, and suitability with the policy of Mosul University Central Library. The study includes three parts: the first part deals with the general frame of the study, the second deals with the theoretical part, the third tackles the field work. The researcher selected a random sample of books available at the Central library shelves which have CIP data prepared by Iraqi libraries, centers or publishers which mounted to (100) books to be analyzed depending on the descriptive method. The study concluded that there are multiple institutions responsible for CIP inside the country and the absence of central institution and shortage of compliance of these institutions with the cataloging international standards and large ratio of mistakes and differences in their data Consequently the central library can not depend on such data until it makes some modifications on it to comply with the Library policy and the description level practiced in it.