¡§Kaohsiung Farm Irrigation Association¡¨ is taken as the researching topic. By means of ways of interviewing and documents reviewing, to observe how does the farmers from farm society make communicating relation through this farmer, unit by the nation¡H And how is the reaction of farmers from farm society to the sovereign of the nation¡H In the relation of mutual action between nation and society, the Water Conservancy Association is sometime the agent of idea and the executive of policy of the nation, also sometimes the unifier of farmers, opinions in farm society. This dual status makes the Water Conservancy Association the governmental and private function. So the Water Conservancy Association is the unit of half-official and half-civil. From the mutual action of association working station and farmers, we could find out why the nation to dominate this association. The farmers are controlled under the Water Conservancy Association and this Association will be the bridge between the nation and farmers. As to the function why the nation try to dominate the Water Conservancy Association, we could see the function of economical politics to be reached from the mutual action between the Association and farmers and the role the nation acted in the irrigation system. In the function of economical aspect, the Association meaning of existing is to promote the crop production and the quality of crop to improve the living level of farmers to reach the purpose of service. In the function of political aspect, the Association will be acted the important role during the election event. For example of ¡§Kaohsiung Farm Irrigation Association¡¨, it has been classified as the Red Party since Taiwan Restoration. The organization system of the Association is very tight and the member are numerous. The organization of this Association has the structure of Administration Dept., Working Station, Water Conservancy Team, Water Conservancy Section and basic members. Under the complete organization system, the chairman of this Association will control the huge power of the farmers, hence, the Water Conservancy Association is acted as the influential role of politics in the current society system. Anyway, the Association is still to be acted as the important role of ¡§election¡¨ in the function of politics. The Whole sovereign will be performed and realized by the particular tool or means. The nation is also not excepted. Because the nation controls the ¡§power of allocating the social resource¡¨ and ¡§personnel power of appointing ¡® removing to the chairman¡¨, the social qroup of this association could be under controllng. In other woeds, the Water Conservancy Association is under governing of the nation. and the nation policy could be performed even the farmers are dominated by the Association just because the above mentioned two powers and owned by the nation. Finally, the future developing direction of the Association will be discussed in this article. The Water Conservancy Association will face the transferring industrial society from agricultural society. The agricultural production will be largely reduced and the farming area will also be gradually decreased. In another aspect, after entering the WTO and under the liberalized demanding, the agriculture will be suffered from the serious impact. Under these situations, the farm service of this Association will also face the terrible strike. Plus the current financial trouble of the government, the Water Conservancy Association has to find out its own bright way -- Diversifying Investments.