Objective To evaluate knowledge,attitude and knowledge source on chronic diseases among 4~6 graders in eight Chinese provinces. Methods A stratified random cluster sampling method was used to select study participants.All students in 4~6 grades were invited to complete a questionnaire survey. Results A total of 12 385 4~6 graders were participated in the study.Knowledge level was low:52.3% knew that "overweight/fat lead to hypertension or elevation of blood pressure" but only 7.8% knew about the calculation method of body mass index (BMI).Knowledge level was higher among urban children than among rural children (P<0.05);Sixth grader had the highest rate of correctly answer the question about overweight/fat and high blood pressure,while fifth grader had the highest rates of answering other questions (P<0.05).Knowledge about prevention of chronic diseases was positively associated with correct attitudes (P<0.05).Teachers were considered as the most trustful source of knowledge (47.1%) while TV was considered the most favorable source (27.6%).Among all children,59% reported that their families were the most influential factor for their dietary habit,while 30.2% reported that it was the most influential factor for their excise habit. Conclusions It is more lower of knowledge level about prevention of chronic disease.Intervention programs should involve both school and family.