Objective:To explore the factors influencing the incidence of stroke in an intervention population.Methods:A community based population aged 35 years old or over was cluster sampled from Shanghai Nanhui county.Individuals with at least one risk factor of stroke were selected to receive a cerebral vascular hemodynamic index (CVHI) examination.The patients with CVHI score below 70 were defined as high risk population and they received an intensive intervention based on general intervention for 3years (1999-2001).