In ancient times, it was not that fingerprints could not be recognized by pressing handprints, but because many people could not read and could not recognize words. Therefore, according to fingerprints, fingerprints can be compared manually under certain circumstances. Fingerprint comparison is one of the important evidences in criminal investigation.

As early as the Qin Dynasty, the ancients used seals or fingerprints to verify the integrity of this document. Mainly because the wooden slips at that time were very expensive, and all the important documents recorded in them needed to be kept secret. If you find that the lines of the seal or fingerprint are not completely aligned, you can easily identify whether the file has been opened.

Clever ancients still had a way to identify fingerprints. This way, that is, pressing the lines of the whole palm or the lines of ten fingers, sometimes even requires prisoners to print their own soles as symbols representing themselves.

Fingerprint identification technology was not used when handling cases, but to take care of most people, because in ancient times, many people had low educational level, and some people could only simply draw a few strokes, write a word, draw a cross or draw a circle.

Fingerprint identification technology was based on eyes from the beginning, so of course there was fingerprint identification technology in ancient times.

More than 2,000 years ago, in the Qin Dynasty, China had a record of using fingerprints to solve crimes. Many documents, contracts and wills found in the Tang Dynasty after liberation have fingerprints, knuckles or palm prints as an important means to identify individuals. Since then, all previous dynasties have followed the habit of taking finger mold and palm mold as mirrors in literature.

The ancient army of China had a jump book to register the fingerprints of soldiers for inspection. This shows that fingerprints can be correctly classified by morphology and structure at that time, and this classification feature and knowledge have been applied to social practice.

In ancient society, because there were few literate people, most of them belonged to the elite, so ordinary people had to press their fingerprints in the contract. Because the ancients did not have handwriting identification technology (and many ancient literati took imitating handwriting as their personal hobby), hand (palm) seal became the main source of evidence.