Yuwen Shiji (died 11 November 642[1]), courtesy name Renren, formally Duke Zong of Ying, was a Chinese statesman and politician of the Sui and Tang dynasties, serving as a chancellor, as Shizhong (侍中) (625–626) and Zhongshu Ling (中書令) (626–627), during the reigns of Emperors Gaozu and Taizong of Tang.
He was previously an imperial prince in the short-lived state of Xu (許), which was ruled by his brother Yuwen Huaji.
When Emperor Yang went from the eastern capital Luoyang to Jiangdu (江都, in modern Yangzhou, Jiangsu) in 616, Yuwen Shiji followed him there.
When Yuwen Shu, who also followed Emperor Yang to Jiangdu, fell ill and died later in the year, Yuwen Shiji briefly resigned to observe a mourning period for his father, but was soon returned to imperial service as the deputy minister of imperial supplies.
During this time, Li Yuan, who has himself taken the throne at Chang'an, establishing the Tang dynasty as its Emperor Gaozu, sent secret messengers to Yuwen Shiji, then at Liyang (黎陽, in modern Hebi, Henan), and Yuwen Shiji secretly sent messengers to him as well, offering him golden bracelets—using bracelets (環, huan, a homophone to 還, meaning "return") to show that he intended to support Tang at some point.
Some of Yuwen Shiji's followers suggested that he gather his troops and attack Dou and try to take over the land north of the Yellow River.
He later served under Emperor Gaozu's son Li Shimin the Prince of Qin in defeating Liu Wuzhou the Dingyang Khan, and as a result was created his old title of Duke of Xincheng County, and was given the Princess of Shouguang County (寿光县主, a relative of Emperor Gaozu, although the relationship is not clear) as his wife.
After Dou's defeat, the Princess Nanyang, who had become a Buddhist nun, headed back from the Xia capital Ming Prefecture (洺州, in modern Handan) to Chang'an, and she happened to encounter Yuwen Shiji at Luoyang.
In 627, while Yuwen Shiji retained the title of Zhongshu Ling, he was no longer actually chancellor, as he was made the commandant at Liang Prefecture (涼州, roughly modern Wuwei, Gansu).
Subsequently, he was recalled to Chang'an to serve as Dianzhong Jian (殿中監), the head of the palace affairs bureau (殿中省) – a high-level post, but one not bestowed with great powers.
Later, on account of illness, he was made the prefect of Pu Prefecture (蒲州, roughly modern Yuncheng, Shanxi), but was then recalled back to Chang'an to be a minor general.
When Emperor Taizong reviewed the contributions of the officials to the founding of the Tang dynasty, he rewarded Yuwen Shiji by creating his son the Duke of Xincheng County.