Knowledge is the most important asset for organisations today. Knowledge management (KM) has become one of the most moving research and development fields in information systems (IS), business management and commerce development. There are many researches in the technical and strategic aspect of KM. However, how to model KM is still a big issue. This paper will fill this gap by providing a hierarchical spiral model (HSM) for KM. The proposed model will facilitate the research and development of KM and IS.