There is said to have been over 300 healing symbols in ancient times, but out of these only a handful are used in Reiki. When Reiki was introduced in the west, the symbols was kept secret and passed on orally from Reiki master to Reiki master, and as a result there is now variations on most of the symbols.
The Reiki symbols cannot cause harm or be used with harmful intentions. Many people therefore question the need for secrecy and the symbols are now widely published in books and on the Internet.

CHO KU REI - The Power Symbol or the light switch, Put all the power of universe here.
Directs energy to the physical body.
[ CHO KU REI ]

SEI HE KI - The Mental Symbol is used for purification, cleansing and protection.
Directs energy to the emotional body or subconscious mind.
[ SEI HE KI ]
HON SHA ZE SHO NEN - The Distance Symbol is used to send Reiki to the past, present or future. Healing karma.
Directs energy to the mental body or conscious mind.
[ HON SHA ZE SHO NEN ]
DAI KO MYO - is used both for attunement and healing and it works on the spiritual body level, healing the soul.
[ DAI KO MYO ]
DUMO - is a Tibetan Master Symbol representing the fiery heat of the kundalini.
[ DUMO ]
FIRE SERPENT - is often used when passing attunements.
[ FIRE SERPENT ]