Using the political culture analysis method, this paper discusses the origin, contents and functions of the agriculture encouragement system of the Song dynasty, which originated from the pre-Qin period (221 207 BC). The main content of this system in its early stage is that in the early Spring days, the king symbolically ploughed a piece of land near the suburbs of his capital in order to send to his subjects a clear message of the importance he attached to agriculture. It was expected that peasants would be encouraged by his majesty's guidance, and thus agricultural production of the countryside would be promoted. With the rationalization of the political system since the Qin period, agricultural encouragement gradually became a routine work of the Chinese governments at different levels. Under the Northern Song dynasty (960 1127), agricultural encouragement envoy was added to the official rank of heads of counties and prefectures. They each were required to take the responsibility of persuading peasants in their jurisdiction to work harder in the field. The actual work as an agricultural encouragement envoy in the Song dynasty was to go to the countryside to reward peasants with food and wine in early February, and to write an essay to express his encouragement, and to distribute it to the peasants. Formalistic as it is, the agricultural encouragement system is a typical manifestation of the traditional Chinese political culture. As one of its social impacts on the Song society, it helped the spread of advanced agricultural technology with its institutional basis.