This study aims to identify the extent of the possibility of using the sequential indexing plan in producing alphabetical objective indexes for the classified index in Arab libraries, most of which lack such kind of services that prevent the beneficiary from completing his research and studying well, in addition to the fact that this lack leads to delays in research Studies and their lack of contemporaneity with the latest information in the fields of human knowledge, in addition to the lack of most Arab information sources and scouts, and this is one of the basic problems that the user faces in Arab libraries with regard to Arab information sources. On this basis, this study will answer the following two questions: 1. What are the features of sequential detection and what are its problems? 2. How appropriate is the indexing sequence of Arab libraries? This study relied on the descriptive study of the literature of the subject in the specialized information sources to reveal its features and problems of this plan, in addition to the use of practical examples based on the classification systems used in libraries, and through these examples we can identify the features and problems of the plan in a practical and concrete manner. The study also relied on surveying the opinions of workers in a number of Arab libraries through a questionnaire distributed for this purpose, in order to learn through it the possibility of using this plan in Arab libraries, and to come up with the appropriate results.