Korean ethnic dwellings have changed rapidly with the urban development of China. However, approaches to this kind of rural construction included insufficient architectural space in their design to meet the needs of contemporary life. We therefore need to better understand the spatial evolution of Korean ethnic dwellings and how to best capture their current spatial characteristics. Taking an Architectural Planning perspective, we looked at 38 typical Korean ethnic dwellings in the Tumen River Basin, the ways in which their spatial character has changed, and the behavior of their residents, before summarizing their overall spatial characteristics. The research revealed that, through the influence of other cultures, elements of the plan form of Korean ethnic dwellings have been enriched and have grown in complexity. This has been accompanied by changes in residential behavior. We identified four types of changes of spatial characteristics: simplification and opening up; local changes of use; adoption of policy guidelines; the influence of other ethnic groups. Results of this research might serve as a reference for the future construction of Korean ethnic dwellings and inform research on other ethnic residences, thereby enriching the development of ethnic culture in China.