New towns in Iran are designed to reduce population pressure on metropolises, but differences in goals and implementation have had different effects on their physical structure. This study analyzes the role of urban policies on the development of the physical-spatial structure of Sadra, that located 15 kilometers northwest of Shiraz. This study, with a descriptive-analytical method and an applied approach, used a questionnaire and field and documentary data, and the data were determined through a researcher-made questionnaire of 100 people (professors and experts in the field of urban planning in Fars province) according to the common standards of the regression method to provide a sufficient sample size to achieve meaningful results. The findings show that urban policies, with a correlation of 0.618, explain 61 percent of the changes in the physical-spatial structure of Sadra. The factors of planning and organization (beta = 0.502), decision-making and policy-making (beta = 0.205), and administrative affairs and services (beta = 0.064) have the greatest impact, respectively. Transportation network, citizen participation, and waste management were identified as the most important influencing factors, while weaknesses in maintaining public spaces and institutional coordination are the main challenges. These results are in line with global studies and emphasize the need to pay attention to sustainability, spatial justice, and participation in policy-making.