Harmony state is to make the five viscera help each other and make visce ra and meridian coordinate with each other.ZHANG Zhongjing emphasized the health state that one will be healthy if one’s original qi of five viscera are smooth.Under the premise of asthenia requiring tonification，he paid attention to the method of"supplementing the center and seeking harmony".Based on the theory of balance between yin and yang，the authors analyzed the significance of the method of supplementing the center and seeking harmony of ZHANG Zhongjing in the prevention，health preserving and treatment.There is no need replenishing for those who are in balance of yin and yang.For those who are in state of yin and yang deficiency，they should balance yin and yang in order to avoid making lopsided loss.For those who are in a state involving vital qi and deficiency，they should judge and weigh to promote the body resistance and eliminate pathogenic factors.