This is the first comprehensive companion to the study of Daoism as a philosophical tradition. It provides a general overview of Daoist philosophy in various thinkers and texts from 6th century BCE to 5th century CE and reflects the latest academic developments in the field. It discusses theoretical and philosophical issues based on rigorous textual and historical investigations and examinations, reflecting both the ancient scholarship and modern approaches and methodologies. The themes include debates on the origin of the Daoism, the authorship and dating of the Laozi, the authorship and classification of chapters in the Zhuangzi,  the themes and philosophical arguments in the Laozi and Zhuangzi, their transformations and developments in Pre-Qin, Han, and Wei-Jin periods, by Huang-Lao school, Heguanzi, Wenzi, Huainanzi, Wang Bi, Guo Xiang, and Worthies in bamboo grove, among others. Each chapter is written by expert(s) and specialist(s) on the topic discussed.