This paper is an attempt to explore the technical aspects of Sheikh Abdul-Qahir Al-Jurjani's theory of versification which is scattered in his book Dala'il ul-I'jaz and to collect these dispersed parts. Al-Jurjani's theory of versification represented an outstanding critical and rhetorical achievement in the Arabic critical rhetorical tradition because it provided answers to many critical questions at that early epoch in the history of Arabic literary criticism. It, therefore, attracted the attention of critics and rhetoricians at all subsequent times. Such a theory can never be found in his predecessors except for some hints in Ibnul Muqaffa' and Al-Jahidh's works though the idea of versification was common among the Mu'tazila and Ash'ariya but it was not evident; it was just mere hints which no one had interpreted in detail except Al-Jurjani who gave it much importance and talked about it in details, linking sound to sense, rhetorical figures of speech to the miraculous nature of Qur'anic language. Al-Jurjani's theory of versification has become a scientific basis for the interpretation of the Holy Qur'an. Furthermore, some critics tried to link Al-Jurjani's theory with contemporary stylistics and poetics Due to the fact that Al-Jurjani's theory of versification was the corner stone and an evidence of the development of the Arabic critical rhetorical thought, this paper is an analytical study to explore the technical aspects of this theory depending mainly on his book Dala'il ul-I'jas. Among the technical aspects that formed the theory of versification were grammatical meanings, structure, sound and sense, metaphor and the meaning of meaning. The paper concludes by linking the technical bases in the theory of versification with the contemporary critical approaches.