Abstract: The main goal of this article is to explain how the field of Knowledge Management is affected by The Theory of Knowledge (or Epistemology). Moreover, it proposes the rout of this effectiveness. The initial purpose of this statement is to propose a conceptual model showing the effects of the Knowledge Theory on Knowledge Management and expressing the theorems and rules showing this rout of effectiveness. First of all, for achieving the goal of this article, the literature relating to the foundation of Epistemology is reviewed. By a careful review related to knowledge definition, its categorization and its legalization approach, the direct relation between Epistemology and Knowledge Management is cleared. By reviewing the existing paradigms in Knowledge Management and its related fields, the indirect relationship between Epistemology and Knowledge Management is defined. This relation is determined by paradigms and theories embedded in other related disciplines. These extracted relations are discussed in the form of fourteen extensive theorems and then proposed in a conceptual model. Then, six composed theorems are extracted by combining these fourteen theorems. These six theorems can explain the problem statement. Finally, all theorems are integrated in one main theorem. The final theory is proposed in the form of an initial theory expressing the rout of effectiveness of the Knowledge Management from Epistemology. This model can be used for reviewing and reconstructing Knowledge Management theories and extending this field based on other competitive Epistemologies.