Objective To explore the effect of practice-oriented dementia care training program on improving nurse assistants′ dementia-specific caregiving competence and quality of care in residential aged care facilities. Methods A total of 60 nurse assistants caring for residents with dementia from two residential aged care facilities in Shanghai were selected conveniently, and divided into two groups according to the institutions which they worked, with 30 assistants in each group. The nurse assistants in the control group were trained on relevant knowledge and skills routinely, while the intervention group received a 3-week practice-oriented dementia care training. The nurse assistants′ dementia-specific caregiving competence before and after the training was assessed, and the symptom severity by Neuropsychiatric Inventory of the residents in dementia care unit was collected before and one month after the training. Results After the training,the dementia-specific caregiving competence of the nurse assistants in the intervention group was significantly higher than that in the control group (P<0.01), and the residents scored significantly lower in Neuropsychiatric Inventory than those in the control group (P<0.01 for all). Conclusion Practice-oriented dementia care training for nurse assistants in residential aged care facilities, can improve their competence in dementia care and quality of dementia care, and effectively enhance the overall quality of dementia care services in residential aged care facilities.