Urban agglomerations in China play a big role in the country's economic development. A study looked at how economic differences between regions have changed from 2001 to 2020. They found that overall, the economic gaps between regions and within urban agglomerations are getting smaller. Differences within urban agglomerations contribute a lot to the overall economic gaps. The East region has the highest economic differences among urban agglomerations, followed by the West, Central, and Northeast regions. Some urban agglomerations, like the Pearl River Delta, have more noticeable economic gaps within them. Various factors like location, government policies, human resources, and transportation affect these economic differences.