Red fox, a canine predator inhabiting in the grassland of eastern Inner Mongolia, is positioned near the top of the food chain. It plays an important role in rodent control. Consequently, research on red fox helps scientists accumulate basic data and offers a scientific basis for the protection of grassland ecosystems and red fox management. Red fox habitat selection in the Dalai Lake Natural Reserve was systemically studied from November 2009 to January 2010 and from March to April 2010. Line transects were used for 101 plots known to be used by the red fox and for 144 comparison plots. We processed our field data and analyzed them using principal component analysis. Using landform analysis of the study area and other relevant research work, we defined seven significant factors influencing habitat: vegetation type, sheltering class, food abundance, snow depth, distance to water sources, distance to fences, and distance to residential areas. Our results