Based on the poetry creation of Bai Juyi (772-846)the great poet of Tang dynasty,the article try to analyze what was the different influences of the Confucianism,Buddhism and Taoism to Bai Juyi's thinking and writing. Then the article try to find what was the overall influences of the tendency to Bai Juyi's attitude to life and all kinds of behavior. Taking Bai Juyi as a case,the article also attempted to discuss the similarities and complementarities of the three doctrines in one's philosophical aspect.