"Qi-blood-water theory"was put forward by Yoshimasu Nangai,a Japanese physician of ancient formula school,who believed that diseases were the changes of qi,blood and water.Bi syndrome contains three kinds of poison of qi,blood and water.If the poison hits the qi,it will occur joint pain,fever and muscle atrophy.If the poison hits the blood,it will occur pain fixed,dark purple skin,nodules.If the poison hits the water,it will occur joint swelling deformation,heavy,lingering illness.Guizhi Shaoyao Zhimu Decoction is mainly used to remove qi and water poison and has weak ability to remove blood poison.Professor Chen Baotian jionted Wutou Decoction and Xiaoxuming Decoction,which called Xiaowugui Decoction.Wutou Decoction strengthen effects to remove qi and water poison and Xiaoxuming Decoction is good at removing blood poison.Combination of three decoctions correspond to the pathogenesis of Bi syndrome.Two medical cases were attached for reference.