Abstract: This paper explores the changes in the language ecology of the cross-border ethnic groups with fewer populations, taking the Lao Mian and Lao Pin as examples. They interact with other ethnic groups and were very much homogenized with the local mainstream culture. The internal culture of their ethnic groups shows a trend of diversified development. Multicultural harmony and symbiosis provide an important environment for their multilingual and complementary language life. The Lao Mian speak both Lahu and Hani languages, while the Lao Pin speak Dai, Lahu and Hani languages. With the development of economy, science and technology and the popularization of education, the changes in the language ecological environment have accelerated, and the influence of Chinese culture has become increasingly prominent, and Chinese has become an important tool for local inter-ethnic communication. In the face of the current changes in the language ecology, we have put forward some suggestions on the maintenance of the ecological balance of the cross-border ethnic groups with fewer populations and the protection and inheritance of language culture.

Key words: cross-border ethnic groups, language ecology, diversified changes, protection and inheritance