Execution difficulties and financial constraints are encountered when conducting experiments of full scale evacuation exercises in large scale building. This study focuses on large gymnasiums. The concept of 'Hot Area' is proposed by focus groups of fire experts. The most dangerous spot in a building, Hot Area, is selected and analyzed based on the ranking method. Then, a Hot Area evacuation exercise is carried out to replace a full-scale evacuation exercise. In addition to simulating the Hot Area evacuation in Taipei Arena with Exodus software, an observation of a real life exiting of 2089 people is also conducted. Next, the observation result is compared with the software-simulated result. Finally, suggestions are made to provide a set of reference criteria for inspecting the same type of buildings when their construction works are completed.