The Chai-Hu Zhi-Shi Shao-Yao Gan-Cao Tang is a Jhongjing formula. It was called ”Si Ni San” in [Shan Han Lun] of Song dynasty. The Chai-Hu Zhi-Shi Shao-Yao Gan-Cao Tang specified in [Old Kweilin Shanghan Zabing Lun] is more suitable from the logic and syndrome of Shan Han Lun. Si Ni San is the powder of Si Ni Tang. One purpose of this study is to propose the relevant discussion. The other purpose is to discuss its clinical application.