The project to convert farmland to grassplot for 9.00×10³hm² of the upriver irrigation area of the Tarim Valley is a segment of synthesis management of the Tarim Valley.The project involved 1.42×10³hm² reservoir irrigated area,3.60×10³hm² river irrigated area and 4.00×10²hm² water pump irrigated area. After coverting farmland to grassplot, the gross irrigation water need is less and the water previously used for cropland irrigation becomes available for environmental application. While selfsow nvegetation replaces some cropland, at the same time,the remaining farmland can be utilized for greater benefit. The gross saving of irrigatiion water can approach 3.10×10⁷m³,which can flow to the lower reaches of the Tarim River. Converting farmland to grassplot can have marked benefits for surrounding areas, and is propitious to the improvement of the environment in Tarim Valley.