Abstract: The explanation of the form,meaning and pronunciation of character  “单” in the book "Shuo Wen Jie Zi" is all erroneous.Decoded according to the shape inscribed on bones and tortoise shells asrevealed by the symbols of synchronic charactermaking,the character “单” refers to a set of lassos for catching animals.This conclusion throws light to the explanation of many characters with  “单” as a component part inscribed on bones and tortoise shells and later on bronze objects.

Key words: symbols of synchronic charactermaking, ancient Chinese characters, inscriptions on bones and tortoise shells, inscriptions on bronze objects, lassos