Since the mid 1990s, miracle development of the private and foreign sectors in the Southern economic region of Viet Nam has attracted a large number of migrant flows from the Mekong Delta region and the Khmer migrants have a recognized contribution to those migration flows. Based on the survey of 76 Khmer families in Tra Vinh province where the Khmer is dominant in its total population, this paper examines demographic and socio characteristics of the Khmer families affecting the determinants of migration decision by using of the logistic regression model. This result indicates that migration decision is importantly depended on number of members, plot size, poverty and so on. In addition, this result also points that migration not only brings migrants an increased income, but also contributes positively to their family’s income in rural origin.