Abstract: To accelerate the development of urbanization and agricultural modernization is an important mission of the construction of ‘four modernizations’ in China, study the relationship between urbanization and agricultural modernization is the premise to achieve the balanced development. On the basis of the establishment of comprehensive evaluation index to evaluate the development degree of urbanization and agricultural modernization, the author aimed to use the coupling harmonious degree model to further explore the coordination degree of those two systems in the past 20 years. The results showed that urbanization and agricultural modernization were not independent, they were elements complementary, development interaction and targets inter-amalgamation. Urbanization had a strong promoting effect on agricultural modernization in the initial stage. From 1990 to 2013, Chinese agricultural modernization and urbanization gained great development, and the interaction and synergetic effect was increasingly strong. The coupling harmonious degree of those two systems was 0.53 in 2013, which belonged to the level of primary coordination, and it was estimated that the coupling coordination degree could exceed 0.7 in 2025, which belonged to the level of intermediate coordination, the development of Chinese urbanization and agricultural modernization would enter a spiral up period.