Abstract 
Cultural diversity is one of the main topics in today’s world. As a country with 56 ethnic groups, China’s diversity is a potential source of both joy and worry. The joy comes from the rich and diverse cultures brought by the 56 ethnic groups. However, China also has to face the reality that some of these ethnic cultures are vanishing. One measure to sustain China’s ethnic diversity, ethnic education, has been getting increased academic and government attention in recent years. 
This thesis is grounded in the theory of ethnic education. By employing a qualitative descriptive research method, I describe the language of instruction of Mongolian-medium schools in Tongliao from 2007 to 2015. Then, by employing a qualitative narrative research method, I explore reasons for the varied patterns. Finally, by discussing the problems in the current Mongolian-medium education system, I suggest relevant solutions.