Objective: To investigate knowledge, attitude and purchase behavior for snack nutrition among parents of school aged children in Shenzhen, so as to provide support and scientific basis for developing targeted intervention program for child healthy dietary behavior. Methods: Through cluster random sampling method, a total of 4 517 parents of students graded in 2 from 116 primary schools in Shenzhen were invited to participate into a self administered questionnaire survey. Results: Parental cognition towards snack nutrition varied substantially. The majority of parents were worried about the health and safety issues of snack and were aware of the risk of eating disorder of consistent snakc consumption in children. Only 21.18% of parents reported frequent snack purchasing behaviors. Children s snacks, mainly included milk, dairy products, vegetable, fruit, bread and cake, are mostly purchased by parents, and the snack choices were related to nutrition, hygiene and taste. In addition, most parents paid attention to the production date whereas less than one third of them read the nutrition facts labels. Parents with different knowledge level towards snack nutrition differed in eating attitude and behavior. Conclusion Parents should be further educated about nutrition and food safety knowledge to improve nutritional literacy, as well as attitude towards healthy diet and snack purchasing ehavior to better guide their children to develop good eating habits.