An Overview of Customs is a book written by Ying Shao of the Eastern Han Dynasty. This book mainly evaluates name and description of things, systems, customs and rumors of previous dynasties. The book contains a wide range of content, including records and narrations of national ceremonies such as rites, music and sacrifices, the identification and correction of folk rumors, beliefs in ghost and God, as well as the comments on ancient and modern characters and involves many aspects of life in the Han Dynasty. It is the first-hand information to understand the customs of the Han Dynasty. The purpose of writing this book is to rectify customs, establish a set of codes of conduct and norms in line with Confucian ethics, and purify people''s thoughts, so as to help the Eastern Han Dynasty get rid of crisis and restore normal ruling order.