The Central Place Theory of Walter Christaller, a well-known German geographer, was first proposed in his 1933 book "Central Places in South Germany". The term central point or place is used to refer to a location that supplies goods and services to its surrounding areas, and is thus central to several areas and the source of their needs. In fact, this theory is designed to respond to the spatial distribution of cities and the systems of hierarchy among them, and the centrality of a site increases and decreases with corresponding increase and decrease in the level of service received by that location.
In this paper, first the hypotheses and principles of the theory of Christaller are presented based on whose assumptions it can be said that in this theory all phenomena are placed in their ideal state, something that can be rarely found in reality. After assumptions, the urban hierarchy has been examined; according to his observations on central locations in southern Germany, Christaller found that there is a hierarchical system in the economic and administrative system of these central locations. His belief in the existence of a hierarchy among the central locations of the southern regions of Germany led him to classify them according to their population and degree of centrality. According to the Central Place Theory, the spatial distribution of central places takes shape in a regular geometric space that is displayed in the form of conventional and overlapping polygons (hexagons). After urban hierarchy, the concept of threshold and the concept of the sphere of influence of goods and services in the Central Location Theory, the factors affecting the return of consumers to the central location, the assessment of economic activities in a hierarchical system and the application of central places in regional planning are examined, and after reviewing these cases, Christaller’s theory has been evaluated, and finally a conclusion has been made.