Purpose: This study was to develop a screening model for identifying a high risk group of dementia and to develop and evaluate the web-based prevention program. Method: It was conducted in 5 phases. 1) Data were collected from dementia patients and non-dementia patients in a community. 2) A screening model of the high risk population was constructed. 3) The validity test was performed and the model was confirmed. 4) Four weeks-prevention program was developed. 5) The program was administered, and evaluated the effects. Result: The model consisted of age, illiteracy, history of stroke and hypercholesterolemia. The program was designed with 12 sessions, group health education using web-based individual instruction program, and 12 sessions of low-intensity physical exercise program. After the completion, their self-efficacy, and health behaviors in experimental group were significantly improved over those in the control group. The perceived barrier in the treatment group is significantly decreased. Conclusion: The screening model developed is very simple and can be utilized in diverse community settings. And the web based prevention program will encourage individual learning and timely feedback, therefore it can facilitate their active participation and promote health management behaviors at home.