Abstract: In order to have a systematic understanding of the historical development of corn as well as analyze and summarize the characteristics of the change in layout of corn production in the three major plains since the founding of the People’s Republic of China, and discuss the reasons for such changes, this paper divided the period from 1949 to 2020 into five stages, calculates the corn production concentration index for more than 70 years, and conducts a horizontal and longitudinal comparative analysis of the corn production concentration index of the three major plains. The gap between the corn production concentration indexes in the three major plains gradually increased with change in time, among which the index of corn production concentration in the northeast plain and the north China plain was much higher than that in the middle and lower reaches of the Yangtze River. After 2011, the corn production concentration index in the northeast plain exceeded 40%, which opened up a gap in corn production with the north China plain. In conclusion, the domestic maize production layout continues to gather in the northeast and north China plains, and the concentration of corn production in the northeast plain accounts for nearly half of China’s maize production. After the implementation of the “grain feed” policy and the subsidy policy for corn producers in three northeastern provinces and one district, the area planted with corn in China has decreased, and the corresponding output has also declined.