A comprehensive community-based intervention with health education as the major measure for preventing cardio-cerebro-vascular diseases in selected urban residents in Beijing, Shanghai and Changsha cities during the periods of the ninth "five-year" plan (1996-2000) was conducted, and its effects on knowledge, attitude and behavior (KAB) changes were evaluated by quasi-trial designation. Results show that the net KAB level increases by 6.01 scores in three cities and by 6.12 scores in patients suffering from hypertension after intervention, and these changes in scores are statistically significant. The net percentage of hypertension patients who took blood pressure measurement regularly within every 3 months and the net percentage of them who took anti-hypertension drugs regularly for therapy increased by 9.65% and 7.33% respectively after the intervention and the former increased was statistically significant. It is concluded that health education may promote the improvement of knowledge, attitude and behavior changes of participants and is of great importance for preventing cardio-cerebro-vascular diseases in communities.