Cultural diversity has made Indonesia a symbol in the form of various tribes. So a marriage of different cultures is easy to happen which requires each partner to interact with each member of the extended family of his partner. However in the interaction is not always easy, there are obstacles that limit their interaction, some of the causes include anxiety over mistakes occur in communication and attitude causing misunderstanding as well as uncertainty in predicting the behavior should behave. So this research tries to find out how early marriage couples differ in culture in managing the anxiety and uncertainty they experience when first interacting with each partner's extended family member. The research method used is descriptive study and analyzed qualitatively. This study had 4 informants in two couples, Balinese-Sundanese couples and their extended families. The theory used is Anxiety / Uncertainty Management from William B. Gudykunst. Data collection uses in-depth interviews and observations. Data validity test used is sumbang triangulation. The results of this study that each partner can manage the anxiety and uncertainty that they feel to be down when the first communication with the extended family of their partners caused by positive reception from each family member. So that they are able to understand communication and can interact as they expect, the factors underlying the decline in anxiety and uncertainty are self-concept with the personality traits of the couple's maturity and motivation to be accepted in their partner groups.