Modernization of science and technology is the key to agricultural modernization. The contradiction between supply and demand of agricultural science and technology was discussed in the paper from two aspects of agricultural structural contradiction and the development of quality according to the actual situation of agricultural development in Jilin province. The reasons for the imbalance between supply and demand of agricultural science and technology were expounded from the five aspects including the bondage of mechanism of system, poor input, lack of innovation ability, low conversion efficiency and lack of development stamina, etc. On this basis, ideas and goals of scientific and technological innovation to promote the agricultural modernization development of Jilin Province, and countermeasures to promote agricultural modernization in Jilin province by scientific and technological innovation were put forward from such aspects including deepening the reform of system of science and technology, promoting scientific innovation ability, innovating the mode of transforming scientific and technological achievements,digging into the potential for innovation in agricultural science and technology.