Different treatment for the same disease is that different treatment is based on different pathogenesis namely different syndrome.And the same treatment for different diseases is due to the same pathogenesis in other word the same syndrome.The essence of them is that treatments are based on corresponding syndrome.And the combination of disease differentiation and syndrome differentiation is the precondition of them.Shanghan Lun is the first work about treatment variation based on syndrome differentiation.It contains the principle of them.This paper sets forth them of Shanghan Lun in above-mentioned aspects.