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 sutras based upon several authentic commentaries all in English. The introduction is refreshingly topical. the doctrine of the Guna's-the four fold developmental theory namely physical, mental, moral and spiritual. The eight limbs of yoga, mantra, and laya yogas and their utilities in the presents system have been discussed in details. The book shows how the sutras of Patanjali are nearer to Raj Yoga rather than Hatha Yoga.