Professor Xue Boshou inherited academic and clinical experience of Doctor Pu Fuzhou， emphasized one must be flexible when doing syndrome differentiation and treatment.Professor Xue is especially good at treating acute exogenous febrile diseases.He thinks that Xiaochaihu Decoction has remarkable effects of reinforcing healthy qi and eliminating pathogen， up-bearing shao yang qi， releasing stagnation of qi， and regulating qi activity.Therefore Xiaochaihu Decoction can harmonize and release the exterior and interior， regulate qi activity by up-bearing and reducing， smooth blood flow， balance between yin and yang.In clinical practice， Addition and subtraction of Xiaochaihu Decoction and combination of other formula have even better efficacy for febrile diseases.