The purpose of this study is to recognize effective factors on establishment and strengthening brand and consumer relationships in new social networks and the impact of these relationships on brands. Statistical population of this study is the users of social network, who are followers of the brand communities of food-beverage and cosmetic-beauty industries. Using the three criteria including maximum follower, highest level of engagement, and the amount of activity in the social media, brands of My, Ash, Saharkhiz Saffron and Tekdaneh were selected to be studied. The research method is set in two qualitative and quantitative partss. In analysis stage, through constant comparison process, open, axial and selective coding, Concepts, categories and themes were organized, In the following, using the correspondence analysis, the relationship between extracted themes and demographic variables were found out and native model of relations was introduced. then, in quantitative approach, with performing two quantitative studies in food-beverage and cosmetic-beauty industries using structural equation modeling and hierarchical regression, conceptual model resulting from qualitative study was examined. Findings revealed that motivations of social, functional, monetary, brand related and hedonic are as factors influencing the in creation of interactions between brands and consumers, which are influenced by demographic variables. Also, research findings showed that active participate in social media lead to the creation of trust, commitment, intention to purchase and positive word of mouth.