Xi Zheng, courtesy name Lingxian, was a man of Yanshi in Henan. His grandfather Xi Jian became Inspector of Yi Province at the end of Emperor Ling's reign and was killed by bandits. As the realm fell into great disorder just then, his father Xi Yi remained in Shu; Xi Yi became a Commander under the general Meng Da, surrendered to Wei along with Meng Da, and became a Clerk of the Palace Secretariat. Xi Zheng's original name was Zuan. His father died when he was young and his mother remarried, leaving him alone and on his own, but he was content in poverty, loved learning and read widely in the ancient classics. Records, Shu 12 §81
By about the age of twenty he could compose writings, and he entered the palace as a clerk of the Palace Library, was transferred to Clerk Foreman, was promoted to Gentleman, and rose to Director. By nature indifferent to glory and profit, he devoted himself above all to letters; of the writings and rhapsodies left by men such as Sima Xiangru, Wang Bao, Yang Xiong, Ban Gu, Fu Yi, Zhang Heng and Cai Yong, and of the fine writings and essays of his own day, whatever existed in Yi Province he studied deeply and read almost all of it. Records, Shu 12 §81–82
After he came to hold palace posts, he lived as the neighbor of the eunuch Huang Hao for thirty years. Huang Hao rose from humble origins to high rank and wielded power, but Xi Zheng was neither loved nor hated by him. So his office never rose above 600 shi, but he escaped worry and calamity. Records, Shu 12 §82
According to the Biography of Meng Guang, the Gentleman of the Palace Library Xi Zheng, a younger man of letters, often visited Meng Guang to consult him. When Meng Guang asked about the crown prince's studies and character, Xi Zheng answered that he served his parents reverently and treated the officials with benevolence and forbearance. When Meng Guang said that apart from such things he wanted to know about his strategic sense and wisdom, Xi Zheng answered that the way of an heir lay in carrying out his father's wishes and giving him every joy, that wisdom was kept hidden in the breast and strategy emerged in response to the times, and so could not be determined in advance. Meng Guang understood that Xi Zheng was cautious and did not speak rashly, and Xi Zheng deeply agreed with Meng Guang's words that wisdom came first. Records, Shu 12 §35–37
Following the earlier Confucian scholars, Xi Zheng expressed his views through a composition, which he called Dispelling Ridicule (Shi ji), a work in the line of Cui Yin's Expressing My Intent (Da zhi). In it, when someone mocks him, urging him to seize the moment, achieve merit and leave a name, Xi Zheng cites how Shang Yang, Li Si, Lü Buwei and Han Fei rose high only to ruin themselves, and answers that leaving advancement and retreat to fate and not changing post through nine evaluations is what he has always held to. He says that the court is piled high with men of talent like a mountain, so that the departure of a single bird does not make them fewer, and concludes that, since he cannot match the talents of the men of old, he will quietly keep to himself and live at ease. Records, Shu 12 §83–84 · 88–89 · 95–96 · 98
In the 6th year of Jingyao (263), the Later Sovereign, following Qiao Zhou's plan, sent an envoy to sue Deng Ai for surrender, and the letter was written by Xi Zheng. In the 1st month of the following year Zhong Hui rose in revolt in Chengdu, and the Later Sovereign was moved east to Luoyang. In the confusion and haste, none of the great ministers of Shu escorted and followed him; only Xi Zheng and the Palace Guard Commander Zhang Tong, a man of Runan, abandoned their wives and children and followed alone to attend him. Thanks to Xi Zheng's guidance, the Later Sovereign conducted himself fittingly and was faultless in his bearing, so he sighed with emotion and regretted having come to know Xi Zheng so late, and the opinion of the time praised this. Records, Shu 12 §99
The Biography of Xi Zheng records that he was given the rank of Marquis Within the Passes, while the Biography of the Later Sovereign records that the Director of the Palace Library Xi Zheng was enfeoffed as a full marquis together with the Director of the Imperial Secretariat Fan Jian, the Palace Attendant Zhang Shao, the Grand Master of Splendid Happiness Qiao Zhou and the Palace Guard Commander Zhang Tong. During the Taishi era he became Prefect of Anyang County and was transferred to Administrator of Baxi; an edict of the 8th year of Taishi (272) said that in Chengdu he had held to righteousness through adversity without betraying his loyalty, and that after being employed he had devoted himself fully to his work and shown achievement in governing. He died in the 4th year of Xianning (278), and the poems, essays, rhapsodies and other works he wrote numbered close to a hundred. Records, Shu 12 §100Records, Shu 3 §52
Xi Zheng wrote an essay assessing Jiang Wei. He said that although Jiang Wei held the weighty office of senior general, his house was shabby and he had no wealth to spare, and he kept neither concubines nor music; this was not something he forced himself to do to set an example for others, but because he considered that enough. To disparage Jiang Wei because he died and his clan was destroyed, he said, ran counter to the meaning of praise and blame in the Spring and Autumn Annals, and Jiang Wei, who loved learning tirelessly and was upright and frugal, was a model for his age. Records, Shu 14 §49–50
In his assessment Chen Shou named Qiao Zhou and Xi Zheng together, saying that Xi Zheng's writing was brilliant, with the air of Zhang Heng and Cai Yong, and that in his conduct too there was much a gentleman would value. He added that the two men were included in this chapter because they did little under Jin and much in Shu. Records, Shu 12 §102