As a symbol, cognitive style, a kind of deep structure, xiang has its unique connotation. The formation of the theory about xiang in zhouyi mainly have three points. One is wu culture in xia and shang as the prototype of the theory. Myths and legends provide basis of the method. The second is the Zhou Dynasty music culture specifing its value orientation. The third is the pre-qin thought promoting its philosophy connotation of Zhou Yi.