Although the demand of functional foods is increasing rapidly, and Vietnam is considered as a much potential market for the development of functional food market. However, there are many unsolved problems remaining in functional foods market, and these problems have never ceased to draw public attention and provoke debates. Thus, the purpose of this research is to investigate the factors affecting to consumers' attitude and how consumers' attitude affecting to consumer's repurchase intention. The research will be conducted based on the questionnaires' results collect from people who have used functional foods in Ho Chi Minh City,Vietnam. Questionnaires will be spread to consumers by hands and online survey. There are 260 responses are valid. The results show that there are four factors that positively affect to consumers' attitude. These are (1) Consumers' knowledge, (2) Perceived role, (3) Trust, (4) Subjective norms. Moreover, the findings also show that when people have positive feelings about products, they will increase their intention to products. Research also finds that trust is a direct relationship with consumers' repurchases intention. From this conclusion, the study gives some recommendations to increase consumers' attitude towards functional foods as well as the repurchase intention.