The old county of Nanchang, according to Tang Yan Volume 5, Surprised Before Trying, the first sentence of Wang Bo's Preface to Wang Tengting is "Nanchang Old County, Hongdu New Residence". The Old County of Zhang Yu was originally written by the Tang Dynasty in Zhengcang Hospital in Nara, Japan, and was edited by the envoys of the Tang Dynasty. This manuscript, originally kept in Masakura Hospital in Nara, contains Wang Bo's 4 1 preface poem.

Wen Yuan Huaying was a famous figure in the Northern Song Dynasty. Because Tang Ben's Collection of Wang Zian has long been lost, Preface to Wang Tengting is included in Wenyuan Huaying, the original text is "yu zhang (Nanchang Works) Old County". It can be seen that both versions existed in the Song Dynasty.

There are two reasons for this name:

1, taboo means:

After Tang Daizong Li Yu came to power, in order to avoid the emperor's anonymity, "Old County of Zhang Yu" was changed to "Old County of Nanchang". As a result, people gradually got used to the saying of the old county town of Nanchang. Even the existing stone tablet of Wang Tengting says "Nanchang Old County".

2. The change of Nanchang's administrative status and the ambiguity of place name interpretation;

Those who support "Nanchang old county, Hongdu new house" think this sentence is more reasonable to explain: Nanchang is the location of Zhangyu County in Han Dynasty; Hongdu was the seat of Hongzhou Prefecture in Tang Dynasty. Preface to Wang Tengting is a parallel prose, which is undoubtedly very appropriate according to the antithesis principle of parallel prose. However, those who support the old counties in Zhang Yu believe that when Wang Bo wrote this preface, Nanchang was already a state and a prefecture rather than a county. There was no Nanchang County in history, only Zhang Yu County, Nanchang Prefecture and Nanchang General Administration.