Background and aim: Nowadays, attention to the safety of the city and its citizens is one of the top priorities of city managers and planners. Planning and designing urban environments and evaluating the role of the city body in reducing urban crime has been the subject of this study. Therefore, the main purpose of the present study is to investigate the impact of proportionality of urban mass and spaces on the quantity of crime occurrence in Behbahan city. Research methodology: This research in terms of goal is applied research and in terms of methodology, it is descriptive-analytical based on literature review and field surveys. The statistical population is the collection of crimes of robbery, murder, purse, prostitution and rape, which is occurred in 2015. The required data were obtained by referring to the Behbahan city police stations and aerial photographs taken by the UAV. In order to produce a map of the mass and space of Behbahan from captured images, UAV images were standardized by Agisoft photoScan software and then converted to map by ArcGIS software. Kernel Functions and geostatistical tools from Spatial Analyst Tools were used to perform data analysis of crime rate and spatial analysis. Findings: The results showed that the total area of 23, 488, 034 square meters of the city, the urban mass and space occupy 7. 542. 299 and 15. 973. 475 square meters respectively. Therefore, the proportion of the mass to the space in the city is not complied, and the volume of the city's mass and texture is greater than empty spaces, and its focus is on the central part of the city; In a way that the areas around the city and the outskirts of the city constitute vacant spaces. This reflects the heterogeneity of the physical texture of the environment. Conclusion: The proportion of mass and space in the city of Behbahan has not been respected, such that as it progresses to the city outskirts and the empty spaces around the city, the incidence of urban crime is reduced and the highest rate of urban crime occurs in the urban masses and denser textures of the central part of the city. This indicates the influence of environmental texture on the quantity of crime occurring in the city.