| As the basic of three major industries, agriculture is weaker, agricultural production is high-risk and the return is uncertain. And in our country, the farmers face the two basic conditions that land is small-scale land and the produce of product is extensive. Because of that, the income of producing product is poor. Although the transfer of rural labor has increased the income of farmer, and the industry income of farmers has become an important part of the income of farmers, this does not fundamentally solve the problem of low income of agricultural production. The development of farmer cooperatives has brought a new opportunity to improve agricultural production and incomes for farmers.From the functions, the cooperatives have played a great role in the development of agriculture and the increase of farmers' income. However, with the development of the cooperative, we also face many problems. One of them is that the applicability of the cooperatives. The role of the cooperatives is to increase household income, so the characteristics of agricultural products and the market transaction costs have decide the development of the cooperatives.That the standardization of product is difficult to determine, has decided the characteristics of agricultural diversity, has determined the variability of prices of agricultural products;occult quality characteristics of agricultural products, has made the agricultural markets prone to "lemon market" phenomenon; that agricultural production is often scattered determines the agricultural products will be decided at a very low level;the large supply of agricultural products in a short period of time, is easy to form a situation of oversupply, resulting in a large number of agricultural prices fell, while at other times, due to lack of supply, the price of agricultural products becomes higher, causing the result of the agricultural price volatility.Cooperatives can cause the direct cost lower by making the farmers together, and thus formed a large-scale production needs. By making a long agreement with the vendor, the farmers of the cooperative can get a lower price o production, thus making famers get the direct cost.Another role of the cooperatives is to reduce the indirect input costs, mainly to reduce the cost of the additional time spent on the research of productions.In addition, the development of cooperatives through the brand will also promote the improvement of household income. Because of the occult quality of agricultural products, the actual demand of consumers purchase for agricultural products is lower, while the emergence of cooperatives brings a guarantee to consumers, promotes the increase of demand for agricultural products, thereby increasing the real income of farmers. And in order to pursue long-term development, the co-operatives often pay more attention to their own brand development, and the impress of the consumers, in this case, it will increase the demand for agricultural products.In order to verify the theoretical hypothesis, with the characteristics of grape production, this paper has studied the roles of cooperatives of grape in increasing farmers' income, and tried to find the economic theory behind it. We has find three cases, including: the Jurong Dingzhuang Grape Cooperative, the Beijing's Xinte Cooperatives, Changzhou Lijiaxinnan Grape Cooperative.In order to deeply develop the cooperatives, this paper has give the following policy recommendations:raising awareness of farmers on cooperatives; setting and improving the cooperative law to help develop a set of good management system, making preferential policies to develop appropriate agricultural development, giving farmers a relaxed policy environment; giving the cooperative some help, such as finance, taxation, and other aspects of the project to develop the cooperative; establishing a cooperative dialogue with the Government departments to help the cooperative to solve their problems. |