This study explains the mechanism of the village institutional capacity and the level of cooperation within the irrigation organization on the irrigation system supply． Using the data of 883 households in 6 provinces of the Yellow Ｒiver irrigation area，the paper empirically tested the effects of institutional capacity and cooperation level on farmland irrigation system supplied by farmers and its action path． The empirical results show that the three levels of institutional capacity factors of knowledge resources，relational resources and mobilization capacity in the field of village space have a significant positive impact on the willingness and degree of farmers to participate in the supply of irrigation systems. The level of vertical cooperation and horizontal cooperation within the irrigation organization has a significant positive impact on the willingness and degree of farmers to participate in the supply of irrigation systems． The study further confirms that the cooperation level between the institutional capacity and the supply of irrigation system has a regulatory effect. The higher the level of cooperation，the stronger the effect of the institutional capacity on the supply of irrigation system. Based on the conclusion of the study，the author puts forward some measures such as attaching importance to the village institutional capacity and strengthening the awareness of cooperation within the irrigation organization to improve the supply of irrigation system． 

Keywords: Institutional Capacity; Level of Cooperation; Agricultural Irrigation System; Double Hurdle Model