Wang Jishan was born in 618, around the time of the founding of Tang Dynasty. His family was from Ming Prefecture . His father Wang Jun'e had, at the end of Tang's predecessor Sui Dynasty, served under the agrarian rebel leader Wang Junkuo , and after Tang was founded, surrendered to Tang with Wang Junkuo and subsequently served as a Tang general. Wang Jun'e participated in 's , and died in 645 during the Battle of Mount Zhubi . Emperor Taizong posthumously created him the Duke of Xing. After Wang Jun'e's death, Wang Jishan inherited the title of Duke of Xing and was given the additional honorific title of ''Chaosan Daifu'' .
During Emperor Gaozong's reign
During the reign of Emperor Taizong's son , Wang Jishan served on the staff of his son and crown prince Li Hong. Once, Li Hong gathered his staff members for a gave of ''zhidao'' . When Wang's turn was up, he opined that there were people whose responsibilities were to entertain the crown prince, and that it was inappropriate for staff members to be participating in the game. Li Hong thanked him and excused him. When Emperor Gaozong heard this, he awarded Wang with silk and made him a commanding general of the imperial guards, commenting, "I know that you are faithful and diligent, and that is why I give you an office of the third rank. Other people need to be searched before they could enter the palace, but you are allowed to holster a large sword to be by my side. Do you understand the honor that this is?" Soon thereafter, however, Wang was dismissed on account of illness, but later on was made the minister of military supplies .
During Wu Zetian's reign
In 690, Empress Dowager Wu had Emperor Ruizong yield the throne to her, and she took the throne as "emperor," establishing a new Zhou Dynasty and interrupting Tang. During a Khitan attack in 697, Wu Zetian requested Wang Jishan to come out of retirement to serve as the prefect of Hua Prefecture , stating to him, "The thieves on the border have rebelled. Even though you are ill, you can head slowly to your post 30 '''' a day ) with your wife and children. Even if you can only govern the prefecture while lying on your bed, you can cut off the Yellow River for me." She then inquired him as to his opinion on a number of central government affairs. He gave her some 10-odd items of opinion. She, in turn, responded, "A prefecture is unimportant compared to the important matters of the central government. You must not leave." She then made him ''Neishi'' , the head of the legislative bureau of government and a post considered one for a . Later that year, when her secret police official Lai Junchen were accused of crimes warranting death and yet she considered pardoning Lai on account of his contributions to her in the past, Wang pointed out that Lai had falsely killed many virtuous officials and that he must be killed. Wu Zetian agreed and executed Lai.
It was said that Wang was not well-studied, but was honest and upright in his acts. Around 699, at imperial feasts, Zhang Yizhi and Zhang Changzong were often not acting in accordance with proper regulations for imperial subjects, and Wang often counseled Wu Zetian not to allow them to carry out these actions. This displeased her, and she told Wang, "You are old. It is not right that you be required to attend so many feasts. From now on, just tend to the matters of the legislative bureau." Wang, in turn, claimed illness and requested sick leave. After taking leave for a month, Wu Zetian had not yet tried to see him. He sighed and stated, "How can the Son of Heaven not see someone as important as the head of the legislative bureau on a daily basis? This shows how unimportant I am viewed." He then requested retirement, but she did not approve of it. Instead, she made him ''Wenchang Zuo Xiang'' , one of the heads of the executive bureau , and gave him the designation of ''Tong Fengge Luantai Sanpin'' , having him still serve as a chancellor ''de facto''. He died a month later and was buried with honors, near the tomb of Emperor Gaozong, where Wu Zetian herself would eventually be buried as well.