In language in general and in Vietnamese and English in particular, address terms are the reflection of the hierarchical relationship among participants of the conversations as well as their attitudes and emotion. In order for the conversation to go smoothly, speaker should choose suitable address terms basing on the relationship between listener and speaker. The choice and usage of suitable address terms with the context and content will depend on this interpersonal relationship; these address terms also have impacts on the development of the conversation. It is, therefore, meaningful and important to conduct a research into the respective expression of form of address in the two languages (English -Vietnamese).