白虎，中国古代“四灵”之一。

　　　汉代人把虎看作百兽之王，相传当一只虎满五百岁时，它的毛色才会变白。所以白虎就成了神物。白色代表西方，所以白虎为西方之神。

　　　White tiger is one of the four spiritual creatures. （See below)

　　　Tiger was considered as the king of the animals in Han dynasty. And the old saying went that the tiger would turn to white till it was 500 years old. So the white tiger was thought as the supernatural. For the same time white represents the west. Therefore the white tiger is the spirit of the west.

四灵 The four spiritual creatures

　　“四灵”是中国人对动物的最古老的分类。人们根据动物的飞、走、行、游，羽、毛、鳞和天、地、水、土等性状特征及活动范围，将它们分成鸟、兽、虫、鱼四大类别，每类找一个代表，于是就产生“四灵”。同时， 四灵的形成又与古代天文学的发展联系在一起，殷代前后，古人把春天黄昏前后南方的若干星辰想像为一只鸟形，东方为一只龙形，西方为一只虎形，而北方为龟蛇形象。到了春秋战国，人们又将“四灵”标上了颜色，即青龙、白虎、朱雀、玄武。

　　Long long ago, ancient Chinese people sorted animals into four categories ( bird, beast, worm and fish ) according to their characters of flying, walking, moving , swimming , feather, plume , scale and their regions of living (sky, river, land ). Then they select one animal as representation of each category. This is the origin of the four spiritual creatures. With the development of the ancient astronomy, the four creatures were connected with star constellations and directions. About Yin dynasty, people thought that the configuration of star constellations in the east liked a dragon, south bird, west tiger and north the union of tortoise and snake. When it came to the Warring State , people added one color for each creature. From then on green/blue dragon( 青龙 ) ， white tiger ( 白虎 ) ， red bird ( 朱雀 ) and black tortoise/black union of tortoise and snake( 玄武 ) were frequently painted on the walls of the early Chinese and regarded as the four spiritual creatures of the celestial having the apotropaic function of warding off the evil spirits.