Abstract—As it is obvious , the space can affect on individuals behavior and their life by different ways and also it is possible that it is provided the cultural and social promotion arrangements of society by the principal and correct planning and the design of defensible urban spaces , and how often , without attention to these spaces , the society creates a bed for crime and criminal growth that its result is the creation of undefensible urban space , that it is an obvious and visual affair in our big cities and societies . in this paper, it is considered to theories and key concepts of theorists in defensible urban space field and place effect on crime. These theories occasionally realize each other and /or it has been other authors' theories supplementally and in its direction, that its aim is to achieve concepts and frame which can conduct us to gain and the design of defensible urban space. In this research, after categoring the theories of authors in this field, it will abtain a key concepts that one can be used it for minimizing the crime in spaces. Also, in this paper, it is preceded to the reasons of unfeasible urban spaces. A typical sample of this research, it is Shiraz saadi district that unfortunately, the term of social physical, it is as one of the unsuitable contexts of this city. By attention to being quality and quantity of this study , the research method has been as books studies and literature inverstigation and also questionnir reperation with the focus of defensible urban spaces utimatly , it is applied comparative analysis method. Keywords— space, defensible urban spaces, defensible space, security. I. INTRODUCTION nfortunately, nowadays most society people have unsafty and fear feeling such that, many parents transform the fear to own children and consequently, the family lives in stress and much anxiety during the day and night. in this way, they generate many solutions for own private security creation, including the installation of rails on walls, barded wires, destrict guards, closed- orbit cameras and so on, which all of them are a response against invasion and aggression to the privet properties. But, are really these so personal solutions, only security respondence in the social dimensions? Beside, in many areas and unsafety destricts, ajron bars and barded wires aren’t responder any more. according to survey that it was performed from 200 person of shiraz citizens in related to the reasons of fear and unsafty, 91 percent of them had unsafety and fear sense in city Farzaneh. Hosseini Bagh, master student in Azad University of Shiraz, Shiraz, Iran. (corresponding author to provide phone: +989177100861; e- mail: Mahsa_hosseini99@yahoo.com). Mohammad. Parva, Assistant Professor in Azad University of Shiraz, Iran. enviroments , that is can be said bravely , many of these cases are rised by invironment . The most reasons of fear that it can be said approximately were uniform in all our statistical community consists of following factors: 1.putting empty the house duration several days or even midday. 2. Sending children to school and or to other places alone. 3. Going women out alone at night and or even with campanion. 4. Walking in scilent routes. 5. Walking at night and fear of rubbery. 6. Parking car out of home at the night but, a point that was attractive in this case , old people were who didn’t fear almost and they enable to walk in that distrist easily without any fear even at night, but, families specially women feared strongly from mentioned factors. A. Defensible urban spaces: The consept of defensible urban space was entered the urbanization area for the first time about 60s. It means that, when the urban security is felt that we can provide essential instruments for making defensible spaces: a space that people make satisfaction, comfortable and security feeling. in fact, citizens confidence is due to don’t fearing them from any threat and risk (both mental , visual) against the different factors of city builder such as urban space , residential complexes , installation , green public space and soon that create unsafety feeling in citizens (pourjafar, 2010: 66). Jan gehl (2010) in the city human's book divides the security in two categories: 1. Traffic security. 2. Security and safety in society. According to him, the presence of car has caused the routine anxiety and fear of citezens. He also believes that streets existence riding bicycle and walking priority is nesseccery in an ideal city and quality for people and pedestrians' security must be form key considerations. He divides the security in two general and partial dimensions that the total dimension considers to support and the maintenance of all economical social groups, and the partial dimension considers to the design of partial solutions for security creation in city. If defence of private environment changes to a general discussion about security sense while walking in the space, an exact relation will be seen between the aim of city life reinforcement and requirement to security. If city life is reforced such that humen have gone in communal space and they spend time, almost in all situations, it will increase Both the real security and sensational security (Goal , 2010 : 98). Comparative Investigation of Defensible Urban Public Space with Shiraz Saadi District Farzaneh. Hosseini Bagh, and Mohammad. Parva U 5th International Conference on Chemical, Ecology and Environmental Sciences (ICCEES'2014) Jan. 13-14, 2014 Penang (Malaysia) 23