The objective of the study in first part is to measure the degree ofinternational capital mobility of Thailand both before and after financialliberalization in 1989. The result find that degree of international capital mobilityof Thailand after financial liberalization has a higher level than before that from0.23 to 0.43 or increase 87 %. It 's indicate that Thailand hasa higher open economicsystem. The objective of the study in second part is to test the relationship betweennet foreign capital inflows and gross investment, with gross national savings andsavings by economic sectors. The results show that net foreign capital inflows have apositive impact on gross investment. In contrast, that foreign capital inflows impactgross nationai savings in a negative sign. By economic sectors, the results find thatnet private foreign capital inflows have a negative impact to households' s savingsbut impact on corporated businesses' s savings and financial sectors' s savings in apositive sign. Furthermore, net public foreign capital infiows impact government' ssavings in a negative sign. Thailand has a higher open economic system. Capital inflows continue increase.But from this result showed that net private foreign capital inflows impacthouseholds' s savings in a negative sign. Since households' s savings are the mostimportant component in gross national savings and trend to be decline. So thatgovernment has to find the ways how to increase households' s savings level passthrough government' s policy instruments.