Professor Yan Xiaopings academic thoughts of “prevention first” in treating rheumatism is embodied in: 1) early tonification in kidney would strengthen bones to slow bone damage;2) paying attention to construction and defence to avoid repeating relapse;3）Fortifying movement of spleen to dispel the dampness and disease touching; 4) right constitution diagnosis and different medicine to different patients; 5) paying attention to roots of innate and acquired constitution, and harmonized regulation on spleen and kidney; 6) medicine compatibility including both cold and warmth, to prevent illness; 7) close observation on “dynamic system” and “conghua” rule of rheumatism to prevent the changes first with the medicine.