The eternal Upanishads represent the profound essence, the succulent juice and the perennial spiritual philosophy of the Vedas, expounded and elucidated to make them practical and accessible for spiritual aspirants. They are magnificent, stupendous, forceful and powerful instruments in the hands of true seekers that provide spiritual foresight and vision of the ultimate truth and reality. The Upanishads are integral part of the vedas; each Veda has a number of Upanishads in it. The present series classifies these Upanishads in true vedic tradition. i.e. they are listed and separated into different volumes strictly according to the Vedic sequence and the Vedas they appear in. Each verse of each Upanishad has been extensively explained using simple language supplemented by elaborate notes so that these profound metaphysical treaties can be made accessible to even a lay man. Towards this end, extensive appendices have been added to elucidate the different concepts in simple words. Concepts such as OM, Naad, Naadis, Chakras, Yoga, Atma, Viraat, Moksha etc. are all elaborately explained in these separate appendices, a mantra index in roman is also included. The present volume contains 32 principal Upanishad of the Krsna Yajurveda. The sequence of their listing in this volume strictly follows the sanction of the Upanishads themselves, as is clear in Muktikopanishad, Canto 1 vers no.55. The Atharva Veda's eight Kandikäs (sub-sections), from 31 to 38, of the Gopatha Brahmana are collectively known as the Gayatri Upanisad. These eight Kandikäs have been numbered 1-8 for the sake of convenience here. It is conversation between sages Maudgalya (who belonged to the lineage of sage Mudgala) and Gläva Maitreya (who belonged to the lineage of sage Maitrayu). It reveals the great knowledge pertaining to the Supreme Being, called the Savita, whose visible manifestation is the celestial Sun and other primary units upon which the entire edifice of creation and its auspicious survival is based, such as the fire, wind, moon, day, heat and warmth, clouds, electric, Prāna (life consciousness factors), the Vedas and the fire sacrifice. The dynamic aspect of this Supreme Being is known as Savitri much like the rays of the Sun which help to spread the heat, energy and light of the latter even to the farthest corners of the world. A famous Mantra dedicated to the Sun God is also called Gayatri Mantra because of the fact that it was the first such Mantra revealed by the creator Brahma in the composition style called Gayatri and became synonymous with it. There are other Upanisads with a similar line of exposition, such as the Savitri Upanisad of the Sama Veda tradition, and Brhada Aranyaka Upanisad (Canto 5, Brahmana 14) of the Sukla Yajur Veda tradition.