yes, the fellow up there has the right answers…i do know the chinese probably started it all as they were the first civilizations (everyone else was drawing on cave walls and wearing horns on their heads).

Check these sites out below-

Asian Dragons (See Link 1 Below) -

The earliest representations of dragon-like creatures are Shang and Zhou period (ca. 16th – 9th centuries BCE) bronzes and jades bearing abstract animal or monster designs. By the Warring States or Han period (ca. 8th century BC to 3rd century AD), dragons were frequently painted on tomb walls to ward off evil spirits. Beginning in the late Tang period (9th century), the dragon was painted in ink monochrome (suibokuga ???). The so-called “Nine Dragons Hand Scroll” (Kyuuryuuzukan ????, 1244, Museum of Fine Arts, Boston) by Chen Rong ?? (Jp: Chin You, act. 1235-58) exemplifies ink painting of the subject in the Song period.

Western Dragons (See Link 2 below):

Perhaps the earliest evidence, however, is found in a prehistoric cave at La Baume, Latrone, France. Discovered in 1940 by Siegfried Giedion, some scientists have dated the cave at 20,000 years ago (I do not accept such ancient dates). Peter Costello writes, “dominating the whole scene is a serpent over three metres in length.” As Costello notes, this picture of a dragon-like creature “appeared at the very dawn of art,” whatever its exact date.

At Lydney Park on the banks of Severn in Gloucestershire, England, a mosaic floor of Romano-Celtic origin has been excavated. It appears to be a temple associated with the river cult of Nodens, “the cloud maker.” Prominent in the mosaic are sea monsters that may well be considered dragons.