A cities main structure is equal to its basement and makes it unique and different. Theoretical framework of studying urban structure is concentrated on the theory of urban morphology. Urban morphology is a systematic consideration of frame, shape, map, structure and functions of urban built texture and its origin and style of development, in pass of time. The theory of planning based on analyzing traditional cities, to obtain manufacturing process according to buildings and open areas classification, form their primary position to present changes, is call "space syntax". According to this fact that, a city reflects cultural developments, a cities' active history is considered based on what is built. The method of urban textures withdraw contains streets and blocks, and is the main tool of it. This method is a combination of German and Italian morphology classes, and is considered as an interior/ recognition approach. The main structure is an approach with holistic view to urban texture and takes its generality. This approach completes studies of urban texture and clears relationship between parts and their role in forming a whole. In this article, we propose to combine the study of urban structure development, with the theory of main structure, to obtain a holistic process. The outcome process can be used, in a part of city that has most of identities and characters of whole city through studying this part of city. We can obtain a general recognition of whole structural characters, of the cities.