The Qin dynasty saw the standardization of small seal script, or xiaozhuan, for official use.
The Qin state’s writing developed during the Eastern Zhou period, when different Chinese kingdoms used divergent character forms. After Qin Shi Huang unified China in 221 BC, the new empire treated writing standardization as part of its broader political program, alongside unified weights, measures, and currency. Forms associated with Qin scribes were promoted while many regional variants were discarded.
The chancellor Li Si is traditionally credited with systematizing the script and helping promulgate it through primers such as the Cangjiepian. Small seal script became the formal script of the Qin empire, although it did not remain the everyday script forever. During the Han dynasty, clerical script became more practical and widespread for routine writing, while small seal continued in formal, monumental, and seal-carving contexts.
A common mix-up is calling the script simply “seal script” without distinguishing it from earlier, broader seal-script traditions often grouped as large seal script.