There are 19 Upanishads deals, describes vividly about Yoga :
This Upanishad is taught by a sage called Swethaswadhara. Emphasis is given in teaching Sankhya yoga and the philosophy of illusion(Maya)
This talks about meditation on Hamsa mantra and is being taught by sage Gauthama to sage Sanathkumara. The method of meditating on the Hamsa mantra is fully described.
Amrutha bindu Upanishad
It gives the knowledge of athma in the tasty form of nectar and gives it as briefly as a dot. It tells us about what is Brahmam and other concepts of hard core Hindu Philosophy.
This describes the way and detailed method to chant the holy letter "
Kshrika means knife. It is so called because it cuts ignorance using the knife of wisdom. This is a Upanishad which in detail tells about Yoga and its practice.
This Upanishad is the teaching of Lord Paramashiva to his son Subrahmanya .Talks in detail about Yogic practices, defines Chinmathra Swaroopa ,Athmanubhava , Jeevan Muktha etc
Nada Bindu Upanishad
Tells in detail about the meditation on Omkara (pranava). The method of meditation and some problems which may occur are pointed out.
Dhyana Bindu Upanishad
The meditation on Pranava and Ajabha Gayathri is dealt in
detail along with the method involved.
Teaches methods of attaining Brahma through meditation .Emphasizes role of Guru. Tells that Sruthi is more important than pramana.
Tells about Kundalani and yogic practice.
This is the teaching of Lord Vishnu to Lord Brahma.. It details out the yogic practice. It also tells about the stages in yoga, defines them and tells how to recognize them.
This is the teaching of Lord Surya to a Brahmin called Trishiki Brahmana. He clears his doubts about the definition of the body, soul, Karana and yogic practice.
Yoga Choodamani Upanishad
Tells about Yogic practice involving Ajaba Gayatri. Tells about the seats of yoga , tells how to wake up the Kundalani and reach her up to Brahma Randra.
This is the teaching of Sun God to his disciple Yagna Valkya. This deals with the principle of the soul through yogic practice. Definitions of various terms used in Yoga is also given. Tells in detail about Yogic practice and tells us about what is Sambhavi Mudhra.
This is taught by sage Atharvana to sage Sandilya.. It deals with Ashtanga yoga and Brahma Vidhya.
This is the teaching of Lord Maheswara to Lord Brahma. It deals with subjects like Mukthi, Shakthi, Nadha , Chaithanya and Yoga.
This is the teaching of Lord Dathathreya to his disciple sage
Sankriti. And tells how the yoga should be done in detail.
Confirms that the knowledge "That this Sun is Brahma" would be realized by chanting of Ajapa Gayathri. Tells what is the merger of mind with Brahma.
Tells about the Brahma Vidya of the body of Varaha. Lord Vishnu
as Varaha tells how he should be meditated upon and worshipped. Also
deals in detail about the stages of yoga.