In order to explore the ways to prevent from the disease, 4,793 subjects aged over 40 at high risk of stroke from a total population of 250,000 in communities with high incidence of it were studied with multiple factor intervention, by oral administration of "Nao An" capsules as a major measure in 10 areas of north and northeast China, as well as Shanghai, during 1990 to 1993. Three years after intervention, incidence of stroke decreased by 49.17% in the population, with reduction of systolic and diastolic blood pressure, levels of blood sugar, cholesterol and triglyceride. Lowering of stroke incidence correlated positively with that of blood pressure in the population. It suggests stroke can be prevented effectively by concentrated efforts in comprehensive intervention in individuals at high risk.