The present book comprises the Sanskrit text in Devanagari and transliteration and English translation of the Yoga Sutras's of Patanjali, an introduction, an appendix and notes on each sutra based upon several authentic commentaries all in English. The introduction is refreshingly topical. The doctrine of the Guru's - the four fold development theory namely physical, mental, moral and spiritual. The eight limbs of yoga, mantra, and laya yogas and their utilities in the present system have been discussed in details. The book shows how the sutras of Patanjali are nearer to Raj Yoga rather than Hatha Yoga.