This thesis is based on the hypothesis that Abhidharma is intrinsically concerned with spiritual praxis realization, and that the Abhidharma-mahāvibhāṣā, the supreme authority for the orthodox Sarvāstivādins, provides details of all the fundamental methods of Buddhist meditation, together with their doctrinal basis. The introductory chapter defines the purpose, scope and sources for this study, and examines the origin and nature of Abhidharma, emphasizing it as being essentially a soteriology. Chapter 2 offers a survey of the topics discussed sequentially in the Abhidharma-mahāvibhāṣā, and lists the sections which deal specifically with meditative praxis. Chapter 3 introduces the community of meditation masters within the Sarvāstivāda school, known as the yogācāra-s, and outlines the different stages on the path of spiritual progresses taught in the school. Chapter 4 begins the first topic specifically concerned with meditation, śamatha and vipaśyanā, showing their distinctive nature and contribution to meditative praxis as well as their complimentarity. Chapter 5 deals with samādhi, a key doctrine of meditative praxis, and focuses particularly on the set of three samādhi — śūnyatā, apraṇihita and ānimitta. Chapter 6 discusses the five hindrances which constitute obstruction to progress in meditative praxis. Chapters 7 and 8 discuss the Sarvāstivāda analysis of the meditative practices considered as antidotes for specific personality problems, and in this context introduce the two most fundamental Buddhist meditations — “mindfulness of breathing” (chapter 7) and “contemplation on the impure” (chapter 8) — known in the tradition as the “two gateways to immortality”. Chapter 9 turns to the meditative praxis on the refinement and sublimation of emotional energies, and discusses in details the four “immeasurables”. Chapter 10 discusses another fundamental teaching of meditative praxis, “the fourfold application of mindfulness”, emphasized as “the direct way” to the purification and emancipation of sentient beings in the Sūtra as well as the Abhidharma. Chapter 11 introduces the doctrine of the nine sequential meditative attainment — the four dhyāna-s, followed by the four attainments in the sphere of immateriality, ending with the cessation meditation. Chapter 12 is specifically devoted to the discussion on the four dhyāna-s as constituting the main content of what may be termed the genuine Buddhist meditations. Chapter 13 puts together two major topics of meditative praxis that remain to be discussed. Chapter 14 is a statement of the conclusion of this thesis, in the light of the analysis and discussion in the preceding chapters, that Abhidharma is intrinsically concerned with meditative praxis. It also confirms that the Abhidharma-mahāvibhāṣā is a valuable source book for the study of meditative praxis in the Sarvāstivāda tradition.