A b s t r a c t A r t i c l e I n f oThe observation was conducted to investigate the species diversity and composition structure of indigenous fruit trees on pumonean (growing fields resembling forests) belonging to the local community of Mentawai. Data were collected from the Village Matotonan of District of South Siberut and the Village Bojakan of District of North Siberut using the quadrant method, which were randomly selected and inventory the fruit tree species within are plots. All trees with diameter at breast height (1.2m) of ≥8cm were identified. The contribution of families (relative abundance) and the Importance Value Index of the fruit tree species were calculated using standar formula.The results show that in pumonean were found 14 families, 18 genera and 24 tree species. The high relative abundance of family is found in Euphorbiaceae, Bombacaceae and Meliaceae, which is 12.50%. In general the status of the 15 species of fruit trees are indigenous trees and only three exotic species. Based on Importance Value Index that D. zibethinus (22.43%) and D. carinatus (20.41%) are the dominant species and saved in pumonean. Considering the high species diversity of indigenous fruit trees on pumonean, it is necessary to immediately conserve its programmed effort.