Dragons symbolize different thing in different parts of the world.  
    In China and some other Eastern countries, the dragon is a symbol of strength and wisdom.  It symbolize the forces of nature and the universe and are benevolent.  It brings good luck and blessings.  The dragon was a symbol of the Chinese emperor.  Often times in Oriental designs the dragon is seen wielding the pearl of wisdom, essentially the essence of the universe, in order to control the winds, rains, and the planets.  One Chinese dragon guards the dwelling of the gods.
    In the west, especially Europe, dragons are evil creatures that kill, eat virgins and hoard gold and jewels in there hidden caves.  At first, the dragon was a symbol of the water god and the sun god.  It was supposed to have control over the destiny of man and that is how it came to be feared and considered evil.  It is sometimes associated with the devil.  In the Bible, Leviathan is a dragon that wraps around the earth and bites his tale and holds the world together.  That doesn't sound evil.  That is more a symbol of the cycle of life, creation and recreation. 
    In Babylonian mythology, the dragon Tiamat is regarded as the mystery of Chaos, primal and uncontrollable, passionate in her unchecked creative energy. She is the frightening Unknown of "formless primordial matter" sacrificially recreated as the very beauty of Earth itself. That sounds like the Gnostic goddess Sophia.
    One of the most important dragons of creation mythology is the Australian Rainbow Serpent, its symbol being the rainbow bridging Heaven and Earth. Given the Dream time is connected to our world, the creation story of the Ancestors and their mythical past is simultaneously the creation of the present and our future. According to Aboriginal cosmology the link must be maintained if our future is to be made manifest.
Quetzalcoatl, the Feathered Serpent from South America is another dragon symbol.  In Aztec and Toltec culture, he sought to end human sacrifice and introduces agriculture, music dance and other arts.  He was said to be the link between heaven and earth.