改元即年号的更改，是中国古代一种常见的政治行为。武则天由太后登位称帝的做法可谓前无古人，后无来者。在无例可循的情况下，她探索出了一条新的执政途径——用改元传递政治信息、把政治意志渗透到国家的社会生活中，从而达到扩大权力、稳定统治的目的。从光宅到神龙，武周用改元宣告了政局变更的风向、进行了女主秉政的建构、完成了对事功的自我夸耀，也用年号传达了丰富的历史信息。从太后临朝到女主称制，光宅和垂拱改元是武则天称制道路更进一阶的信号；从革唐之命到还政于唐，天授和长安、神龙改元是武周政权由鼎盛到衰微的风向标。为减轻女身执柄带来的舆论压力，武周从佛教和儒教两个角度推进系统性的女主秉政建构：佛教负责舆论营造，推广女身为王和符谶瑞应的理论；儒教负责观念渗透，附会三代之周、昭示天命承继。改元将这一建构过程完整记录，并通过年号扩大感召力，促进这一建构在武周社会的全面深化。在封建帝王体制下，君主的政治行为也不可避免地受到帝王个人主观影响，武周改元对武则天的帝王心理同样有所反映。

The changing of the era name, known as gaiyuan in Chinese, was a common political practice in ancient China. the practice of a female emperor, such as Wu Zetian, ascending to the throne and changing the era name was unprecedented and unparalleled in history. Without a precedent to follow, she explored a new way to govern - to transfer political information and strengthen people's memory of major political event with changing the title of a reign, so as to expand power and stabilize the rule. From Guangzhai to Shenlong, through the changing the title of a reign, Wu Zhou announced the direction of political changes, carried out the construction of female governance, record the meritorious deeds, and also conveyed multitudinous historical information. From the reign of the Empress Dowager to the rule of Empress, the transformation of Guangzhai and Chuigong was a signal that Wu Zetian's system of roads advanced to a higher level. From reforming the Tang Dynasty to returning power to the Tang Dynasty, Tianshou, Changan, and Shenlong's transformation were a preview of the Wu Zhou regime from its peak to its origin. To alleviate the pressure of public opinion caused by the act of a woman becoming an emperor, Wu Zhou promoted the systematic construction of women's governance from the perspectives of Buddhism and Confucianism. Buddhism was responsible for creating public opinion and promoting the theory of women as kings and auspicious omens. Confucianism was responsible for the infiltration of ideas, attaching importance to the Zhou Dynasty of the Three Dynasties, and proclaiming the inheritance of destiny. The changing the title of a reign fully recorded this construction process and expanded its appeal through the reign title, promoting the comprehensive deepening of this construction in the Wu Zhou society. Under the feudal imperial system, the political behavior of monarchs was inevitably influenced by the personal subjective factors of the emperor. The change of era name during the Wu Zhou period also reflected Empress Wu's psychological state as an emperor.