What is the Heihe–Tengchong Line?

The Heihe-Tengchong line is a imaginary geographical and cultural division used in China to distinguish between the more developed eastern part of the country and the less developed western part. The line roughly demarcates the border between China's eastern and western regions based on historical, economic and cultural differences. The term is derived from two cities: Heihe in the north-east and Tengchong in the south-west.

The Heihe-Tengchong line is often used in discussions of China's regional development policy. The Chinese government has implemented various initiatives to address these regional imbalances, promote economic growth in the western regions and reduce poverty.

https://en.wikipedia.org/wiki/Heihe%E2%80%93Tengchong_Line