Nowadays, infrastructures play a significant role in the safety process in ordinary times and during the crisis. From this point of view, maintaining the safety of infrastructure against threats would be a security priority for any country; therefore, understanding current situation and vulnerability of infrastructures in a regional scale can be used as an efficient mechanism to formulate regional and national security strategies. This paper assesses the vulnerability of infrastructures with passive defense approach and analytical method, in Yazd province. The analysis of data and information collected were done with analytic network process model (ANP) and geographic information system (GIS) due to the interaction between infrastructures. The results showed that about 51 percent of province area is in the situation of high and very high vulnerability. The central part of the province, Yazd and Meybod, is the most vulnerable regions, because of their failure to comply with principles of passive defense, favorable environmental conditions, further concentration, centralization of infrastructure, and political, administrative, and geographical centrality.