Grounded theory is one of the qualitative research methods that is considered for creating a theory from the reality in a holistic approach. 
In fact, every research methodology is based on a set of epistemological principles that validate produced knowledge. Qualitative research methodology has been often explained by phenomenological epistemology in Persian texts. Although it can be true, grounded theory is explained in terms of pragmatism and symbolic interactionism lessons of its inventors. This study reviewed these two points of views in order to make a deeper understanding of grounded theory as a methodology.
Desk study and logical reasoning were applied for the study. The results show the ontological assumptions about the complexity of reality and relation of subjectivity and objectivity suppose knowledge as a part of it’s subject. These epistemological principles lead to the main principles of grounded theory: replacing samples by participators, growing from Part to whole, assuming researcher as the research tool.