Purpose : This study identifies factors related to the workplace violence and violence protection system of apartment security workers. Methods : The data collection was conducted for 10 days at the end of September 2021. The list of medium and large sized apartments was selected in the 7 metropolis of the nation through the apartment management information system. The data on 182 security workers in 14 apartments in the final 5 metropolitan cities were analyzed. Results : Mean age of the workers was 65.55±6.29. 85.2% were 24-hour alternate-day workers. 69.8% were short-term workers for 3 to 6 months. Security workers with work diseases were a high-risk group than those without work diseases in work·customer’s physical assault and violence protection system. Autonomous management in the psychological violence of customers, physical assault of work·customers, and violence protection system has statistically significant risk. There were statistically significant regional differences in work·customer’s physical assault and violence protection system. Seoul was the riskiest region in violence protection system. Security workers in the general security system were statistically significantly riskier group in comparison with those in the integrated security system in work·customer’s physical assault. Conclusion : Security system change from general security to integrated security in the apartment could reduce physical assault of work·customer. Autonomous management apartment could be explored in risk in workplace violence. To reduce workplace violence, work protection system is necessary such as program application, establishment of violence protection department, and violence protection policy.