The major challenge that, the Higher Education Institutions (HEI)s are facing, at present time, is the unproductive management of information, therefor the implementation of Knowledge Management System (KMS) becomes a must to provide many profits to students and lecturers with updated information as well as documented records as an evidence that reflects the process of improving of the whole performance sooner or later. Instead of manually controlling the information process, the dynamic development of ICT has made it possible for HEIs to adapt their processes to be electronic-based. One system that gives this issue a lot of thought is KMS, but because users have refused to use it, it hasn't been widely embraced. This paper will shade lights on the effective factors of the decision adaptation-rejection of KMS. This study is a collective one, provides a serious review of the related lecture regarding this issue. Based on interviews that had been conducted previously and hosted KMS experts from many prestigious and important institutions. They focused on eleven factors that play a great rule in making the decision of the implementation of KMS, as suggested by the literature review and technological adoption theories. Experts have validated these factors and put them in ranks. From these results, a comprehensive integrated implementation conceptual model of KMS that developed to serve the Iraqi HEIs and lead the performance to the next level by the adoption of technology