Abstract: During Qing Dynasty, mountain areas of Yunnan rose an upsurge of development along with a lot of immigrants flooded into and settled down. The immigrants exploited mountain areas of Yunnan and consolidated the frontier of our country, meanwhile, also brought some problems to us at the same time, especially the population problem, ecological problems and poverty issues. In this paper, we scrutinize this historical event with an introspective vision in order to take warning from history.