National Basic Livelihood Security System (NBLSS) has protected the poor for twenty years after 2000 introduction. The aim of this study is to assess the impacts of NBLSS on the lives of poor people. Several analyses are conducted to address the impacts. First, changes in demographic characteristics, poverty rate, and other welfare programs along with internal changes in NBLSS rules and implementation has somehow affected the long-term caseload of NBLSS. Second, the poverty reduction effects of NBLSS benefits have strengthened after the 2015 NBLSS reform, due to increased number of beneficiaries and demographic changes. Third, the results from differences-in-differences analysis imply that 2000 introduction and 2015 reform of NBLSS might have increased expenditures. Forth, despite moderately decreased rates of welfare exit, the quality of welfare exit might have improved after 2015 reform.