It is not known when Guo Zhengyi was born. He was from Ding Prefecture. He passed the imperial examination during the reign of Emperor Taizong, and subsequently served as a mid-level official at the legislative bureau of government, as well as an imperial scholar.
During Emperor Gaozong's reign
In 678, Tang forces commanded by the chancellor Li Jingxuan, suffered a major defeat at the hands of Tufan's general Gar Trinring Tsendro, and the major general Liu Shenli was captured. In light of this major defeat, Emperor Gaozong asked his officials for the proper response against Tufan. Guo Zhengyi advocated going on the defensive for several years while regathering the people's strength, a proposal concurred in by other officials Liu Jingxian and Huangfu Wenliang, and Emperor Gaozong accepted the proposal. In 681, Guo was made the Mishu Shaojian, deputy head of the archival bureau as well as actingZhongshu Shilang, the deputy head of the legislative bureau. In 682, he was given the designation Tong Zhongshu Menxia Pingzhangshi, making him a chancellor de facto. It was said that because Guo had been at the legislative bureau for a long period and was familiar with how it was run, most of the edicts were drafted by him, and he was considered capable in this. In 683, when Emperor Gaozong became seriously ill, he had Guo, along with Pei Yan and Liu, assist his crown princeLi Zhe in handling important matters of state.
Emperor Gaozong died in late 683 and was succeeded by Li Zhe, but Emperor Gaozong's wife Empress Wu served as regent and empress dowager. Soon after Emperor Zhongzong's ascension, around the new year 684, she made Guo Zhengyi the principal of the imperial university, no longer a chancellor. Just a short time thereafter, Emperor Zhongzong, who displayed signs of independence, was deposed by Empress Dowager Wu and replaced by his brother Li Dan the Prince of Yu. For the next few years, Guo was moved between several positions—first as the prefect of Jin Prefecture, then the deputy head of the archival bureau, then acting prefect of Shan Prefecture. He was serving as the prefect of Shan Prefecture as of 689, when Xu Jingzhen, the brother of Xu Jingye the Duke of Ying, who had led an unsuccessful rebellion against Empress Dowager Wu in 684, was captured after spending several years in hiding. During the interrogation of Xu Jingzhen and Zhang Siming, a county magistrate who had assisted Xu Jingzhen in his years of hiding, Xu and Zhang implicated a large number of officials—hoping that by doing so, they would be spared. Among those who were implicated were Guo, along with other key officials Zhang Guangfu, Zhang Chujin, Yuan Wanqing, and Wei Yuanzhong. Zhang Guangfu was executed, but Guo, Zhang Chujin, Yuan, and Wei were spared and exiled to the Lingnan region. Guo, however, died while on the way to exile or in exile, and his assets were confiscated.
