PURPOSES : The purpose of this research was to present quantitative assessment items for each response phase, and to develop a virtual training method that police can use as a tool to effectively counter chemical terrorism in a crowded facility. METHODS : In this study, domestic and foreign documents related to counterterrorism action and virtual training, as well as a police checklist for counterterrorism simulation, were examined. RESULTS : A new checklist for counterterrorism drills was created; this checklist provides details regarding the tasks, trainees (team), execution, and accuracy at each phase based on the counterterrorism simulation checklist in Annex 4 of the Act on Safety Action at Facilities Vulnerable to Terrorism. CONCLUSIONS : This study demonstrates the necessity of virtual counterterrorism training for police, and provides basic data that can be used for counterterrorism manual development/supplements, and virtual training system development.