Uluguru Mountains is one of the Eastern Arc Mountain blocks that stretch from Taita Hills in Kenya to Udzungwa Mountains in south-central Tanzania. The Uluguru Mountains contain several forest fragments, which are recognized as important biodiversity hotspots. The population pressure and encroachment threatens their biodiversity values. This study analyses (1) species richness, diversity, floristic similarity and structure of trees species (DBH = 10 cm) in the forest fragments in Uluguru, (2) Understory species composition and natural regeneration of the fragments (3) changes in species richness, diversity and tree density along the edge-interior gradient in the fragments and (4) indigenous tree use, use values and human population impacts on tree density and species richness in Uluguru forest fragments.