Pottery pieces and stone vessels unearthed at the Zhuangqiaofen archaeological site in the eastern province of Zhejiang push "the origin of the written language back 1,000 years", the state-run Global Times newspaper reported.
The inscriptions predate the oracles, writings on turtle shells dating back to the Shang Dynasty (C.1600-1046BC), which are commonly believed to be the origin of the written Chinese language system.
Some of the inscriptions were written together in what some experts believe resembles a short sentence.
Li Boqian, an archaeology professor from Peking University, said the symbols reveal the ancient Liangzhu civilisation -- which existed in Zhejiang and neighbouring Jiangsu in the Neolithic Age -- had already developed the basic structure of sentences from independent words, the Global Times said earlier this week.
Other specialists dismissed the significance of such a find. Xu Hong, an archaeology researcher from the Chinese Academy of Social Sciences, expressed scepticism on links between the inscriptions and the development of Chinese script.
"Even if those signs on the stones were characters, they were simply from a long dead east Asian country before the Middle Kingdom existed," he said on Sina Weibo, China's version of the social network Twitter.
"Many signs and character lookalikes earlier than the oracles have been found in east Asia."
Xia Jingchun, a professor of Chinese language from Beijing Technology and Business University, also wrote on Weibo: "It's long been believed by experts that there were more ancient characters than the oracles, because the oracles were too mature, and older languages are supposed to be less developed."
The inscriptions were found among artefacts unearthed between 2003 and 2006, state media said.