From the Wikipedia page on Neolithic signs in China [1]

Another group of early symbols which many have compared to Chinese characters is the Banpo symbols from sites like Banpo, just east of Xi'an in Shaanxi province, dating from the 5th millennium BCE, and nearby, at Jiangzhai, in Lintong County, from the early 4th millennium BCE. As the Banpo symbols were discovered fairly early (1954–57) and are relatively numerous (with 22 different symbols on 113 potsherds), these have been the focus of the most attention.

Some scholars have concluded that they are meaningful symbols like clan emblems or signatures which have some of the quality of writing, perhaps being primitive characters, while others have concluded based on comparisons to oracle bone script that some of them are numerals. Still others feel they may be ownership or potters' marks.

Finally, some scholars sound a note of caution, calling such conclusions unwarranted or premature. This is because all the Banpo-type symbols occur singly, on pottery and pottery fragments, unlike written words, which tend to occur in strings representing language. Thus, there is no context from which to conclude that the symbols are actually being used to represent language. Furthermore, there is no evidence of the phonetic loan usage and semantic-phonetic compounding necessary to produce a functional script as seen in the Shang dynasty oracle bone writing. Thus, leading scholars such as Qiu Xigui (2000) argue that:

"What these symbols represent definitely cannot be a fully formed system of writing; this much is quite clear. Is there any possibility that they are primitive writing? Most likely there is not. We simply possess no basis for saying that they were already being used to record language. Nor viewed from the standpoint of the symbols of this same type that continuted to be used following the creation of Chinese script do they even resemble script". (p.31)

"Quite a number of people, basing themselves on the Banpo-type symbols, have said that the history of Chinese writing goes back more than 6,000 years. Such claims are probably unjustified". (p.33).

Qiu also points out that they instead more closely resemble the non-writing symbols which remained in use even into the early historical period. Another problem which has been noted is that, since the oracle bone script was fairly pictorial in nature, if one were to go back to ancestors predating them by over three millennia, one should expect an increase in the pictorial nature of the symbols, but in fact, a comparison of the majority of the Banpo symbols shows the exact opposite to be true. However, it is possible that some of the Banpo or other Neolithic symbols were used as numerals in a pre-literate setting, and it is also plausible that when writing eventually did emerge, some such Neolithic symbols already in use (and not necessarily from such an early site as Banpo) were absorbed into that writing system.

The Wikimedia Commons page, with links, is [2]