At present, there is no reliable evidence to positively prove that the litchi that Yang Guifei ate was produced in Sichuan or Chongqing, but we can disprove that the litchi that she ate could not be produced in Guangdong or Fujian.

We don't have information on how to transport litchi in the Tang Dynasty, but we have information on sending emergency documents in the Tang Dynasty, which shows that:

It takes about 9 days for an urgent document sent from Guangdong to arrive in Chang 'an.

It takes about 10 days for an urgent official document sent from Fujian to arrive in Chang 'an.

The urgent official document sent from Chongqing takes about 4 days to reach Chang 'an.

It's not faster to send litchi than to send it by express mail, is it?

If you know the characteristics of litchi, you will know that litchi can be stored for up to 4-5 days after picking. After this period, it will go bad and cannot be eaten.

The above is enough to exclude Guangdong and Fujian.

In fact, in the Tang Dynasty, although there was no official record, some scholars recorded that the litchi that Yang Guifei ate was sent from Sichuan (near Chongqing) or Chongqing. But there is no record of sending litchi from Fujian and Guangdong to Chang 'an.

There is another fact that can't prove anything, but it is useful for reasoning: Yang Guifei is from Sichuan. She probably liked to eat litchi when she was in Sichuan, so she would ask for an urgent way to send litchi to Chang 'an after she entered the palace.

According to historical records, the litchi that Yang Guifei ate was produced in Fuzhou, which is today's Fuling. Li Zhao's Supplement to Tang Shi records: "Yang Fei was born in West Shu and likes litchi. People born in Shanghai, especially those who are better than Shu, so they gallop forward every year. However, the party is hot in midsummer, and it will be defeated, and future generations will not know. " Xie Fangde's "300 Tang Poems" notes: "When you arrive in Chang 'an, the color and fragrance will remain unchanged, and the imperial concubine will be happy. States and counties are called Italian by the rapid spread of mail. Ma Su is stiff and looks at each other. "Where is Fuzhou? Today is Fuling in Chongqing. It can be seen that the litchi that Yang Guifei ate was not produced in Hejiang.