Potential Dipterocarps Species at Production Forest of Siberut Bhiosphere, West Sumatra. The study of Dipterocarpaceae was done in November 2007 in Siberut Biosphere Reserve. This study conducted on threes sample plot of 0.75 ha in primery forest, logged over area (LOA) <1 year and LOA 5 years. The result showed there were three species of Dipterocarpaceae: Dipterocarpus elongatus Korth., Shorea johorensis Foxw. and Hopea mangarawan Miq. The density of tree and pole in primary forest were about 24 individual/ha and 13.34 individual/ha, there were 9.3 individual/ha and 4 individual/ha in LOA <1 year, than this density were 8 individual/ha and 5.34 individual/ha in LOA 5 years. For sapling and seedling, these densities were about 29 individual/ha and 5.417 individual/ha in primary forest, 5 individual/ha and 3.750 individual/ha in LOA <1 year, 89 individual/ha and 883 individual/ha in LOA 5 years. Community couple between primary forest and LOA wich has similarity index value more than 50%; at tree stage, it was 68,83% comparing primary forest and LOA <1 year; at pole stage it was 62.62% comparing primary forest and LOA 5 years; at sapling stage, there were 53.29% and 66,27% comparing with LOA <1 year and LOA 5 years; at seedling stage it was 88.66% compared to primary forest and LOA <1 year. Similarity index between LOA <1 year with LOA 5 years, there were 60.26% for tree stage, 90.05% for pole stage and 51.13% for seedling stage.