Background: We developed and designed a prototype of a digital reminiscence system featuring Taiwan’s local representative reminiscence elements-memories for caregivers to accompany patients with dementia for reminiscence therapy. The goal of the study is to evaluate the applications of technologies to reminiscence therapy for person with dementia. The system was evaluated for usability and behavior observation from the perspective of patients with dementia, in order to put forward suggestions for the design of the system as a whole. Methods: A total of 19 patients with moderate and low dementia who voluntarily participated in the study were recruited in Changhua area, including 4 males and 15 females with an average age of 76.8 years old. The experiment was carried out with one researcher accompanying one participant for the entire course. In the first stage of the experiment, participants were guided into the experimental situation by chatting about the reminiscence photos provided by participants. In the second stage, researchers assisted participants in system operation and explanation, and encouraged participants to tell their own experiences through the system, record their stories through reminiscence microphones, and share the process with relatives and friends after the activity was over. In the third stage, usability of system was evaluated by questionnaires, and qualitative analysis was carried out in cooperation with semi-structured, open interviews, and whole process audio visual records. Results: This research developed an application system based on Taiwan’s native reminiscence images, which can increase the interaction between participants and companions, and thus, make it easier for participants to immerse the implicit memory of themselves in the system through using. The results show that almost participants had highly accepted the presenting photos by computer, and had a good willing to try the operation of system. Through the digital reminiscence system, the reminiscence photos can be recorded and browsed quickly, and the native Taiwan materials and reminiscence atmosphere provided by this system are considered comfortable, allowing the patient with dementia to remind the fragments of their past life in the implicit memory. Conclusions: This research developed an application system with Taiwan’s reminiscence images as the theme, and discussed the benefits of usability for patients with dementia. Through observation and statistics, it is found that participants had high acceptance of new technologies. Through cognitive stimulation of implicit memory, the system would increase the interactions between the patience with dementia and caregivers. The process of the system is editable and recordable to retain the digital stories of patience with dementia. Finally, four influential factors were analyzed for the usability of the application system for patients with dementia: accessibility, usability, satisfaction, and learning.