This research includes the theoretical framework of formal relations between the components of the plans elements of Khans. Depending on some modern studies in forming relationships, some formal relationships are determined. They are represented by the relationship between the repetitive and unique elements which form the final shape of the building. The scientific method is adopted in addition to the statistical analysis for the purpose of access to the distinctive characteristics of Khans buildings. It is clear from the practical results of this research that Khans buildings are characterized by their participating characteristics by similar properties despite differences in the time period in which the completion of that building, as well as differences in the geographical location of those buildings. This conclusion indicates the unique vision and common background of architectural thought in spite of the change of time and place. The unique harmony of architecture thought determines the identity of Islamic architecture. This indicates the consistency of this architecture that were not documented and does not have the names of the creators who have done it, which by the history evidenced that it is fantastic.