The present study explores the Chinese children's perceptions of TV food and beverage advertising, the influence of TV commercials on their diet behavior and body weight. A questionnaire survey was conducted for a total of 272 students with age 7-12 who live in Fujian, mainland China. It then relates to the age and effect of media use with children’s weight. The discussion is mainly on the children engaged as consumers of advertising, showing their ability to understand the persuasive intent of advertising. It is found that sampled children, aged 9, express the recognition of bias and deception in advertising, while aged from 9 to 12 years old, they progressively develop the cognitive defence. This research intends to study consumer's social learning and the association of TV food commercials and childhood obesity by surveying the perspective of mainland Chinese children. Potential limitations and future study direction are concluded.