Today, for some reasons such as life style, work and shortening the distance, human society lives most collectively and with high population density. Every day the number of old single - family houses is reduced and the number of apartments and towers is being added. An increase in the number of floors of building causes an increase in the number of people living in it, and thus increases the probability of error and incident - for example - fire. On the other hand evacuation of a large number of people from the narrow corridors and steps during a short period of time is unlikely. Therefore determining a safe and quick evacuation plan is of great importance. It is also obvious that investigating any matter requires real data about it. Meanwhile, obtaining real data in this field requires costly maneuvers and time consuming or it is hard to hold maneuvers in some places, and it is impossible to assess projects that have not been implemented yet. Hence in this study such as the majority of the present era studies soft wares and simulations are used. In this study at first different models and approaches used for simulation are introduced and discussed and then a software -based on these models - has been used. In order to asses purposes of this study, all threats and hazards were studied and in order to determine the most likely; experts in the field were polled. In the following seven scenarios commensurate with the possible risks were defined and were simulated in the software. Furthermore the sensitivity analysis on maximum foot and percentage of disabled people as two effective parameters were presented and compared. The results of this study, identifying six critical crossings have been calibrated using statistics data achieved from the first phase of comprehensive study of Isfahan traortation. Keywords: Crowd Evacuation, Risk assessment, Agent-Based Model, Software simulation