Zhanguo Wenzi (characters of the Warring States Period) is a collective name of Chinese characters used in different states during the Warring States Period.

From Jiaguwen (scripts on tortoise shells and animal bones) in the Shang Dynasty (17th -　 11th century BC) and Jinwen (inscriptions on bronze) in the Western Zhou Dynasty (11th century - 771BC) and the Spring and Autumn Period (770-476BC) to Zhanguo Wenzi, Chinese characters witnessed big changes. In the Warring States Period (476-221BC), different states had different written languages and these languages had many differences in structure and writing styles of characters. With economic and cultural development, use of characters was prevalent and writing materials extended to porcelain, bamboo, silk, currency and seal besides bronze ware. As a result, Chinese characters in different areas featured differently.

From a broader sense, Zhanguo Wenzi fell into two systems -- characters of the six states and characters of Qin state. Characters of the six states refer to those characters used in the six states of Han, Zhao, Wei, Qi, Zhu and Yan and some other small kingdoms such as Zhongshan, Yue and Teng, etc. Compared with Jinwen, characters of the six states featured simplified and unbending strokes and rough-and-tumble structures. Characters of Qin state were similar to Jinwen of the Western Zhou Dynasty and the Spring and Autumn Period and they featured relatively uniform structures. Characters of Qin state were called Zhouwen or Dazhuan (greater seal script) by later generations.

Due to different practices in writing languages in different states and different areas, graphemes of Zhanguo Wenzi were in a mess and a same character usually had quite different writing ways.