This book is divided into three chapters. In chapter I, the author provides fully referenced background information about the structure and biology of respiratory syncytial virus (RSV), including genome organization and a brief discussion of each viral protein under separate headings. Chapter II is a study to clarify the role of cell surface glycosaminoglycans (GAGs) in RSV infection. The results of this study show that only certain types of GAGs can mediate RSV infection, the most important being heparan sulfate. The last chapter contains a study to determine the components of heparin/heparan sulfate that are functionally important, such as the level of sulfation, the amount of iduronic acid and the minimal polysaccharide chain length that can function as a receptor for RSV. The results also show that RSV does not contain GAGs in its viral envelope.