Abstract: 【Objective】To explore the spatio-temporal evolution of the main food crops planting structure in the three northeastern provinces.【Methods】Using the decision tree method,based on MOD13Q1 data,combined with crops phenology data and land use data in the three northeastern provinces,the landscape index was used to analyze the spatio-temporal evolution of the planting structure of the main food crops in the three northeastern provinces—maize,rice and soybean.【Results】From 2000 to 2015,the average patch area of maize and soybean in the three northeastern provinces continued to increase,the patch density continued to decrease,and the patch aggregation degree increased on the whole. From 2000 to 2010,the average patch area of rice continued to increase and the patch density continued to decrease. From 2010 to 2015,the average patch area of rice decreased and the patch density increased. From 2000 to 2015,the patch aggregation degree of rice has been in a stable state.【Conclusion】From the perspective of planting structure,soybean was the most important crop in the three northeastern provinces in 2000,and maize was the most important crop in the three northeastern provinces from 2005 to 2015. From the perspective of planting pattern,the planting of maize and soybean in the three northeastern provinces has been relatively concentrated,and the rice planting showed a slight fragmentation phenomenon from 2010 to 2015,but it was relatively concentrated overall.

Key words: The three northeastern provinces, Soybean, Rice, Maize, Planting structure, MODIS