In the last few years the domain of the linguistic inquiry has been enlarged by recent development of the multidisciplinary investigation of language as a communicative tool. Earlier approaches to the study of language concentrated on the study of the sentence as a basic constituent of language. Therefore, the notion of discourse did not receive adequate attention in most of these approaches. Those aspects of language that make text coherent and are no less important than grammatical aspects were not dealt with. The study of language in communication which is called discourse analysis is concerned with various aspects of language that describe it In its actual interactional function. Those main aspects such as textuality, texture and cohesion have dominated the interest of many discourse practitioners in western linguistics In recent years. In Arabic linguistics, the syntactic and semantic signals that link sentences within a text have not received adequate attention. In our modest study of cohesion devices In Arabic we have tried to shed some light on those linguistic features which participate in connecting text parts. We have taken the theory of a nna?m which was developed by 'Abd al-Qahir alJurjani (5 th century AH/l ph century A.D) as the basis for our display of cohesive devices in Arabic text. We have attempted to show that the anna'4m devices suggested by al-Jurjani are of crucial relevance in the investigation and description of certain important characteristics of Arabic text. They are factors which contribute to the coherence of Arabic text and tools which facilitate the evaluation of Arabic discourse coherence. Cohesion IS displayed through four major devices each of which constitutes a single chapter in the thesis. Those devices are attaqdfm wa tta'khfr "fronting and backing", atta'rfJ w a ttankir "definiteness and indefiniteness", a IIJ a d12J "ellipsis" and a 1- wa~ 1 wa IJa$l "conjunctionand disjunction". This study is presented in a manner comparable with Halliday and Hasan's treatment of Cohesion in English.