This book contains 13,000 Chinese words sorted by their frequency of occurrence, allowing you to learn the most important words first. To determine the word frequencies, we counted all words of the Chinese portion of Wikipedia. Word order is never absolute and depends on the underlying corpus (the text collection). However, the order presented in this book is practical due to the linguistic diversity of Wikipedia. The book is not an alphabetically sorted reference, but a guide featuring essential Chinese characters and words for actively expanding your vocabulary. It can be used for both academic and professional purposes.