This research aims to study the relationship and direction of the relationship in the causality of Thai Household Debt and Gross Domestic Product (GDP). The quarterly secondary data had been used since the first quarter in 2007 to the second quarter in 2019. The data are the outstanding loan for housing purchases, outstanding loans for the purchase or hire purchase of cars and motorcycles, and outstanding loans for other personal consumption which made from Bank of Thailand, and GDP was made from Office of the National Economic and Social Development Council (NESDC). Cointegration Tests and Granger causality test are research methodology. The results indicate that the outstanding personal loans and GDP had a long-run relationship in Cointegration tests. In Granger Causality Test, the outstanding loan for housing purchases are significantly determine GDP, GDP are significantly determining the outstanding loans for other personal consumption, and the outstanding loans for the purchase or hire purchase of cars and motorcycles and GDP are significantly determine each other.