In general, geographic foundations are divided into two groups of natural and human foundations. Studies show that the structure of settlement system, while being influenced by human foundations, has been shaped in relation to natural foundations. The results of studying the investigated variables and distribution of settlements show that natural geographic factors have influenced formation of the city of Namin, and geographic foundations such as suitable soil and suitable water resources have had a role in initial locating of the city. In addition to natural foundations, regarding human foundations, functional success also affects settlement system. Functional success, although is dependent upon natural success, includes local, regional, and trans-regional situations too.