Orange was called "Liuding" in ancient China, and its origin can be traced back to the Tang Dynasty. It is said that during the Tang Dynasty, there was an official named Liu Du. During his tenure in Fujian, he found a local fruit similar to an orange, but the local people called it "Liu Ding". Liudu was very curious and asked the local people why the fruit was called "Liuding". The local people told him that the fruit was introduced from the Nanyang region. It was called "Liuding" because it was originally brought back by a person surnamed Liu.
Later, the name "Liuding" gradually spread and became the general name of oranges. During the Ming and Qing Dynasties, the planting of oranges gradually expanded and became an important cash crop. At that time, there were many varieties of oranges, some of which were different in shape and size from Liuding, but the name "Liuding" has been widely used, so it has been used so far.
In a word, orange is called "Liuding" because it was first brought back by a person named Liu. Later, the name gradually spread and became the general name of orange.