There are three stages in the development of lowercase letters. One is the initial peak of Zhong Wang in Wei and Jin Dynasties. The other is that there are many calligraphers in Sui and Tang dynasties and a large number of experts in copying classics; Finally, the revival of the Yuan and Ming Dynasties.
If we say that China was the first person in ancient lower case letters, it can only be listed separately in these three periods, so the first person was Zhong You in Wei and Jin Dynasties, followed by Ou Yangxun in Tang Dynasty, and finally Wen Zhiming in Ming Dynasty.