A study of species richness and diversity of mammal across the elevation gradient of the mountain was conducted in Gunung Stong, Kelantan. The main objective of this research is to determine the number of the mammal species and diversity of mammal across an elevation gradient in Gunung Stong. Several camera traps were used to capture the photographs of mammal in Gunung Stong, with salt as the bait. A total of 83 individuals that consisting of 12 species was detected in all points. The graph of species richness against elevation was in humped shaped. Therefore, 468.5m has the most abundant species compared another elevations. The factors that cause the humped shape graph of species richness along elevation of the mountain are mid domain effect and climate. However, altitude is not the only determinant for species richness; food source, water sources and size of natural forest are also determinants. More study is needed for this study research to obtain more data