1, 55 years after it was introduced into Europe, and 30 years after Jiajing in Ming Dynasty (155 1), the earliest written records about corn in China were published in Xiangcheng County Records of Henan Province.

2. Four years later, in the thirty-fourth year of Jiajing (1555), the corn paid tribute by Yunnan Tusi passed through Gong County, Henan Province on the way to Beijing, and was recorded in Gong County Records.

3. The corn of Ming Dynasty, which first appeared in China's written records, should have been transported to Yunnan Province through southwest routes such as Myanmar, and then entered China.