Inequality and social justice long has been considered by social and humanity sciences and various schools of thought in societies. That is, spatial inequality as one of the important examples of social inequality is unavoidable in allocation of resources and facilities in urban communities. Therefore, what is to be paid attention by urban planners is measurement and affective factors on spatial inequality in order to prevent or to lead to a decrease in rifts between neighborhoods and urban areas. Based on this, present research is done with the descriptive-analytical methodology and with the aim of measuring and analyzing the spatial inequality between the areas of the city of Mahabad with emphasis on the rule of poor tissues and settlements in creating an urban spatial heterogeneous structure. In this paper by using the demographic, social, economic and skeletal indicators, the TOPSIS and the cluster analysis models, different areas of the city of Mahabad are rated and leveled in the year of 1393. Results and conclusions clearly show the unfavorable development of the city of Mahabad. But this unfavorable development doesn't only link to poor and old tissues and settlements of the city. Also, it has been found that not only resources and services are not distributed based on population but vice versa is right. Considering the deep gap between urban areas in skeletal indicator, it can be inferred that the issuing and prioritized problem in the unbalanced spatial structure of the city of the Mahabad is the skeletal factor in which the urban services and facilities is in the top which this has roots in the weakness of performing and exercuting the urban projects.