What is the earliest written language in China?

Wen Tao is the earliest writing prototype in China.

In the prehistoric period and early historical period of China, before the appearance of Chinese characters, the symbol that most resembled characters was Wen Tao. Wen Tao has unearthed a lot of materials, but it has no writing space like Oracle Bone Inscriptions's, only a single symbol. From the Neolithic Age to the late Shang Dynasty, the earliest unearthed Wen Tao was Banpo, Wen Tao, about 4800-4300 BC. In addition, Wen Tao also exists in Dawenkou culture, Longshan culture and Liangzhu culture. Tao Wen is mostly engraved on the black wide band pattern and black inverted triangle pattern on the outer edge of the pottery bowl, and a few are engraved on the outer wall and the bottom of the pottery bowl. Generally speaking, there is only one Wen Tao on the vessel. Academic circles have different views on the nature of these Wen Tao. Qiu Xigui thinks it is a "symbol", Guo Moruo thinks it is a "symbol with the nature of words", while Yu and other scholars think it belongs to the category of words. Mr. Tang Li 'an (Lan) said that Dawenkou culture is "the ancestor of existing characters with a history of about 5,500 years". It is very difficult to decipher Wen Tao. So far, only a few words can guess that it is equivalent to a certain word in later generations. However, Wen Tao is related to Chinese characters, which should be affirmed.