Abstract: An evaluation index system suitable for the evaluation of agricultural water resources vulnerability and food security in China's main grain producing areas was constructed, and the subjective and objective weights were synthesized to determine integrated weights by using D-S evidence theory, and the agricultural water resources vulnerability and food security in the main grain producing areas from 2010 to 2019 were then evaluated. Coupling coordination degree model and relative development degree model were used to analyze the coupling coordination level and the type of coupling coordination development. The results show that, during the study period, both the agricultural water resources vulnerability and food security in the main grain producing areas showed a trend of continuous improvement and optimization, and their scores increased by 6.22% and 17.22%, respectively. The degree of coupling coordination between agricultural water resources vulnerability and food security increased by 5.11%, from barely coordination to primary coordination, and presented a spatial distribution characteristic of "high in the south and low in the north". The types of coupling coordination development of main grain producing areas were mainly low running-backward agricultural water resources and high running-synchronous development. The backward development of agricultural water resources system has become the main obstacles to food security. Therefore, proposals are put forward for the reducing of the vulnerability of agricultural water resources and improving of the coupling development of these two systems.

Key words: agricultural water resources, food security, vulnerability, main grain producing areas, spatio-temporal coupling analysis