The Palace of Nine Perfections (Chinese: 九成宮; pinyin: Jiucheng; Wade–Giles: Chiu-ch'eng) was a summer palace of the Tang dynasty, located in Linyou in the mountains north-west of the capital Chang'an.
The palace was built for Emperor Taizong as a renovation of the earlier Renshou palace built for the Emperor Wen of Sui.
In the second summer (632), he discovered a spring which was dug out and found to provide sweet water.
A stele was erected to record this with an inscription composed by chancellor Wei Zheng and carved by the imperial calligrapher, Ouyang Xun.
This is a famous example of his calligraphy and rubbings are now held by several museums.