This study aims to explore the experience of Vietnamese Marriage Immigrant on teaching the children their own mother language, especially what is the difficulties they have to face, how they are acting during teaching heritage language, and what are the demands of those to reach to a successful heritage education. Through this study, we hope to suggest the foundation materials for the development of teaching heritage language for the international marriage family’s children. This study was conducted using the qualitative case study method and the data collection was done through in-depth interview with 5 Vietnamese marriage immigrants. According to the result of this study, most of Vietnamese marriage immigrants cognize that teaching Vietnamese to their children is necessary, but there are still many difficulties that they face during acting, and visiting the hometown country or using the education facilities are the methods that they hope to be successful in heritage languge education.(Inha University)