Nasopharyngeal carcinoma （NPC） is a cancer prevalent in South China， especially in Guangdong Province. So it is also called the 'Canton Cancer' . Applications of chemotherapy and biological targeted therapy improve control and survival rate of NPC. However， radiation therapy （RT） remains the primary therapeutic method. With the popularization of modern accurate RT techniques， intensity-modulated radiation therapy （IMRT） has been gradually becoming the standard RT technique for NPC. Simultaneously， it brings some problems. For example， more accurate anatomical localization， more precise dosage distribution and stricter protection of normal tissues are required in IMRT. Therefore， there is a pressing need to make a standard for RT now. In Sun Yat-sen University Cancer Center（SYSUCC）， research and treatment on NPC has a history of half a century. And the department of Radiation Oncology has conducted IMRT for NPC patients for ten years. Combining our experiences with. relevant guidelines at home and abroad， we wrote this handbook to supply a clinical reference for the radiation oncologists fighting against NPC.
　　This handbook has the following characteristics：
　　1 There are systemic introductions of screening， diagnosis， staging， treatment and follow-ups for NPC.
　　2 Centered on RT of NPC， the latest international definition of cervical lymph nodes， and the latest guidelines of the National Comprehensive Cancer Network （NCCN） have been amalgamated into this manual. Through comparison of different guidelines， we make a summary for delineation of clinical target volumes （CTVs）， and anatomical definition and dosage limitation of organs at risk （OARs）.
　　3 This handbook also enrolls some new advices for clinical staging and treatment， which might guide clinical therapy and scientific research.
　　We hope that this handbook can be of help in standardization of RT for NPC， improvement of international academic exchange， and progression of radiation oncology research. Sincere thanks be to the contributors and the publishers of this handbook!