Abstract: Objective: The effective prevention measures are put forward, which can reduce the occurrence of security incidents and improve the quality of nursing, by analyzing the causes and characteristics of the safety incident of hospitalized patients with dementia. Method: The occurrence of security incidents which happened in 139 cases of hospitalized patients with dementia from January 2008 to August 2015 were analyzed through the method of the purpose of sampling. Result: The incidence of dementia inpatients security incident showed a trend of decline year by year.139 cases of security incidents had 54 cases of unplanned extubation (38.8%), 44 cases fall/drop of bed (31.7%), 26 cases of trauma/injury in (18.7%), 6 cases of pressure ulcer (4.3%),5 cases of aspiration (3.6%), 2 cases of lost (1.4%), 2 cases of scald injury (1.4%). By analyzing to characteristics of 139 cases of the security event analysis, 67.6% of the events occurred in the night time, 84.2% of the events occurred in the ward, 88.5% of the patients activities of daily living (ADL) was moderate and above dysfunction, 69.8% of patients had high fall risk, 40.3% of patients with pressure ulcer risk is very dangerous. the 66.2% incident occurred when the caregivers accompanied the patients around,40.3% of the incident occurred in the initial stage of hospitalization, 58.3% of patients were subject to different degrees of damage.Conclusion: It can provide the basis for taking effective preventive measures by analyzing the causes and characteristics of the security incidents. It can ensure the safety of patients, ultimately reduce the occurrence of security incidents in hospitalized patients with dementia, and improve the patients satisfaction through effective preventive measures to implement.