Research is a systematic search for information and new knowledge. It serves to essential and powerful purposes in accelerating advances in health. First, basic or traditional research is necessary to generate new knowledge and technologies to deal with major unresolved health problems. Second, applied research is necessary in identifying the priority problem and to design and evaluating policies and programs that will be of the greatest health benefit, using existing knowledge and available resources, both financial and human. During the past decades, concepts and research approaches to support health development have evolved rapidly. Many of this has been describe by specific terms such as operation research, health services research, health men power research, policy and economic analysis, applied research, and decision-linked research. Each of this has made crucial contribution to the development of client-oriented research or health system research (HSR). It is ultimately concerned with improving the health of a community, however defined by enhancing the efficiency and effectiveness of the health system as an integral part of the overall process of socio-economic development. The aim of client-oriented research or HSR is to provide health managers at all levels with the relevant information they need to solve the problem they may face. The participatory nature of such a research is one of its major characteristic because HSR addresses health problem in the broad context: research input from many different disciplines are required. This includes demography, epidemiology, health economics, policy and management sciences, social and behavioral science, statistics, and some aspect of the clinical sciences. With progressive development, the uses of HSR are becoming widely appreciated. As a result, it is being integrated into and applied in special areas of management such as quality assurances, technology assessment, and resource management.