Abstract: In order to study the effects of National Highway 318 on the biodiversity in Gexigou National Nature Reserve, the non-volant small mammals was selected as the research object. 54 sampling plots of 9 altitude zones were set up at altitude interval of 200 m and distances of 0-100 m, 100-200 m and 200-300 m from the highway on both sides of National Highway 318. The species composition of non-volant small mammals was investigated, and the diversity and evenness indexes were calculated. The results showed that there were 18 species, 5 families and 3 orders on both sides of the 318 National Highway in the nature reserve, of which 14 species were found in 0-100 m section, and the capture rate was 4.49%. 17 species of small mammals were found in 100-200 m section, and the capture rate was 6.11%. There were 12 species in 200-300 m section, and the capture rate was 4.95%. The biodiversity index was the highest in 100-200 m section, the lowest in 200-300 m section and the middle in 0-100 m section, which indicated that National Highway 318 had little effect on non-volant small mammals in Gexigou Nature Reserve.