UNESCO has classified Manchu in Northeast China as a critically endangered language. Toponyms can act as carriers of languages and can be preserved for a long time. The Manchu language was the national language in the Qing Dynasty, and there are many Manchu place names in Northeast China that serve as “living heritages” that retain traces of ancient local cultures. We studied Manchu and other related ethnic place names in Northeast China by integrating spatial statistical measures using geographic information systems (GIS) to analyze the endangered languages in the region. The objective was to explore not only the distribution of ethnic toponyms within a relevant historical context but also the environmental factors associated with the endangered Manchu languages. This study reveals that the distributions of ethnic groups and languages can be revealed by the Sinification of ethnic toponyms in Northeast China. The evolution of spatial patterns of toponyms shows the interactive process between Manchus and Han Chinese. The Manchu language is endangered by the influences of Han Chinese migrants on the original culture, as reflected by crops and the distances to the nearest roads, which are indicators of farming culture and accessibility.