Five elements which denotes the five materials 'activity as "metal,wood,water,fire and earth"is the abstract concept illustrating the inter-connection amongst matters and with sweeping connotations as it can define beyond the above said five elements selves . The five element theory uses the five elements ' functions to sum up matters or property of circumstances and states&infers the inter-connection &the rules of the changes of activity of matters &circumstances through the five elements ' inter-breeding and inter-constraints .It believes that all matters are not alone or still but in constant mutual re-inforcing and neutralizing to maintain coordination and equilibrium. Those are the basic definition of the five elements . Those with growing,ascending and smoothing function and property belongs to wood;those with warming and rising function and property belongs to fire,those with load-bearing,generation&transformation and receiving function and property belongs to earth,those with cleaning,descending and restraining function and property belongs to metal and those with freezing ,breeding and downwards-movements function and property belongs to water . The five elements uses the mutual re-inforcing and mutual neutralizing of the five elements to illustrate the inter-connections among matters and it believes that all matters are not alone or still but in constant mutual re-inforcing and neutralizing to maintain coordination and equilibrium. In the application of the medical learning,the theory mainly uses the five elements to analyse and research the five-elements property and inter-connections of the organ,collateral and physiological functions in bodies, and illustrating their inter-play under the pathological condition . Hence,the five elements is not only for the theoretical illustration in Chinese medicine but also bears practical significance of guiding clinics .