What is the name of the calligraphy style that was standardized by Li Si during the Qin dynasty?

The calligraphy style standardized by Li Si during the Qin dynasty was small seal script.

Small seal script, or xiaozhuan, developed from the writing tradition of the Qin state during the late Zhou period. After Qin Shi Huang unified China in 221 BCE, the government promoted Qin character forms as an empire-wide standard. Li Si, the emperor’s chancellor, directed this systematization and helped promulgate the forms through the Cangjiepian primer, traditionally said to have listed about 3,300 characters.

Its characters are generally vertically elongated, rounded, and highly balanced, with fewer regional variations than earlier forms. The script was formal and prestigious, but it was not the only writing style used in Qin administration. More informal, rectilinear forms related to early clerical script were already in practical use among scribes. Clerical script later became dominant during the Han dynasty, while small seal script survived especially in seals, inscriptions, and ceremonial or decorative writing.