This paper focuses on social capital and its impacts to the income of rural household in Vietnam which is rarely studied in literature. In this research we contribute to literature the effects of two different factors, internal and external, of social capital on household income. The multivariate OLS regression model is used to analyse data of the Vietnam Access to Resources Household Survey 2014, with the participation of 3,648 households in rural areas of 12 provinces. This study found empirical evidence that local social capital makes a significant contribution to household income, other than human capital and other household assets, by illustrating four different variables: Interaction between family members, personality of household‟s head, trust and information collected from official institutes and associations. Our findings support a policy of the donors and governments to invest in social capital and provide a proof that there are many other determinants of social capital that are hidden in province-level. | Social capital affects to income of households in rural area of Vietnam