The oracle bones bear the oldest known examples of Chinese script, dating back to the Shang dynasty. The oldest generally-accepted specimans are from around 1200 BCE, the late Shang period. Oracle bones were a divination tool - a piece of bone (large and flat, such as a shoulder blade) or a turtle shell (which had special significance as turtle shells are said to be the origin of the I Ching) was carved with a question and then heated until it cracked. The crack was interpreted and the response (and sometimes, the eventual outcome) were then carved into the bone.

The bones were sometimes used for religious purposes, sometimes as prayers for protection, the outcome of royal births, questions about enemy invasions, battles, and disasters, as well as simply questions about general good and bad luck in the future. They were heated using hot metal rods or burning sticks of wood and fissures appeared on the front which could be interpreted as good, bad, or neutral.

Their discovery was accidental: in 1899 a Qing Dynasty official named Wang Yirong fell ill. He was prescribed 'dragon bones', which were the unearthed bones of dead animals. This time, however, the bones bore inscriptions in odd patterns. Scholars realized their historical significance, dating them to 3,000 years earlier. They had been unearthed in Anyang, in Henan, now known to be the capital of the Shang Dynasty. Today, more than 100,000 pieces of bone have been found, bearing 4,500 different characters, not all of which have been deciphered.

Oracle bones are particularly useful archaeologically speaking because they bear evidence of the age and structure of Chinese writing. The oracle script is similar, linguistically, to modern Chinese, demonstrating a fully-formed writing system capable of reflecting spoken language. The symbols used were pictographic, and they are ancestral to modern logographic symbols. They were much more picture-like than modern Chinese and the language they captured was very similar to Classical Chinese. The complexity of the writing system known as 'oracle bone script' suggests that writing had existed for sometime before the oldest known oracle bones - meaning that there is a longer history to Chinese writing than archaeology has captured.