In June 2005, I met many people from Africa and Europe in a conference in Washington D.C. We spent most of our times discussing poverty reduction and the role of government in sustainable development. We agreed that poor people must have their voices in any Poverty Reduction Program. After the conference, I became committed to finding the answer for the question "why do Vietnamese poor have no right to participate in the recent Poverty Reduction Program (PRP)?" The main objectives of this research are to determine and analyze the underlying constraints on poor people's participation in the PRP in order to more rapidly succeed in sustainable elimination of poverty. In addition, it aims to find out new keys to strengthening the Government's ongoing strategy and developing a framework of collaboration between the Central Government, Local Government and Poor People. Pertaining to the strategy for the obtaining information, interview, focus group, and document review were the main techniques of the research. Data were analyzed by using qualitative method. Interviews were conducted with a total twenty two interviewees represent the PRP leaders, the PRP staffs, and the poor in Ben Tre province, South Vietnam. Three focus groups were carried out among PRP staffs and the poor. The data was calculated and synthesized in to three categories relate to research purpose. I found three main challenges for poor people to participate in the PRP including people's awareness, mechanism, and the poor's characteristics. These challenges must be solved in order to have a sustainable poverty reduction.