Poor pain control is a common problem in health care. Health professionals, clients and family often misunderstand the principle of pain control. The purpose of this paper is to present a case of policy analysis using the Agency for Health Care Policy and Research (AHCPR) Cancer Pain Management Guidelines. The theoretical framework of policy analysis is adopted from the Study of Public Policy by Anderson, Brady and Bullock. The policy process contains five steps: policy agenda, policy formulation, policy adoption, policy implementation and policy evaluation. Besides, an example of policy implementation process is also discussed.