Although certain Northern Buddhist sects set up Vairocana as Adi-Buddha; but before this, he was worshiped as the first of the five Dhyani-Buddhas of the actual universe, and is best known under that form.
The Chinese and Japanese Buddhists of Yogacarya school [in Japan Hosso, Tendai, Kegon, and Shingon sects were founded on the Yoga doctrine] claim that Vairocana transmitted the doctrine of Yoga directly to Vajrasattva, who it is believed, taught to Nagarjuna, the mystic doctrine of Mandala of the two parts [Vajradhatu and Garbhadhatu], which later Nagarjuna transmitted to Nagabodhi, his disciples. Nagabodhi, in his return, taught the doctrine to Vajrabodhi, who transmitted it to Amoghavajra? Vajrabodhi, accompanied by his disciple, Amoghavajra, introduced the Yoga system into China. After his death, Amoghavajra continued the propagation of the Yoga doctrine by transmitting it to various Chinese scholars. All these activities date back in the year AD 720. Toward the end of eighth century, the Japanese sage Kukai went to China to study the doctrine of Yogacarya School with Hui-kuo, and after being initiated into the most secret mysteries of the system, carried it into Japan and founded the Shingon sect.
The doctrine of Yoga was purely esoteric, and, 'taught by means of mystic formularies [tantra] or litanies [Dhahran] or spells [mantra], the reciting of which should be accompanied by music and certain distortions of the fingers [mudra], a state of mental fixit might be reached, characterized by there being neither thought nor annihilation of thoughts [sunyata], and consisting of sixfold bodily and mental happiness [yogi], from which would result endowment with supernatural miracle- working power'. The fundamental principle of the Yoga is the ecstatic union of the individual with Universal Spirit. Vairocana is looked upon as the highest vehicle of the mystic Union and his dharmacakra mudra indicates the mystic Union. It is believed that from him proceeded the element ether [akasa], the organ of sight and all colors. His body color is white.