The study ofDipterocarpaceae was done in November 2007 in SiberutBiosphere Reserve. This study conducted on threes sample plotof 0.75 ha in primery forest, logged over area (LOA) <1 yearand LOA 5 years. The result showed there were three speciesof Dipterocarpaceae: Dipterocarpus elongatus Korth., Shoreajohorensis Foxw. and Hopea mangarawan Miq. The density oftree and pole in primary forest were about 24 individual/ha and13.34 individual/ha, there were 9.3 individual/ha and 4individual/ha in LOA <1 year, than this density were 8individual/ha and 5.34 individual/ha in LOA 5 years. Forsapling and seedling, these densities were about 29individual/ha and 5.417 individual/ha in primary forest, 5individual/ha and 3.750 individual/ha in LOA <1 year, 89individual/ha and 883 individual/ha in LOA 5 years.Community couple between primary forest and LOA wich hassimilarity index value more than 50%; at tree stage, it was68,83% comparing primary forest and LOA <1 year; at polestage it was 62.62% comparing primary forest and LOA 5years; at sapling stage, there were 53.29% and 66,27%comparing with LOA <1 year and LOA 5 years; at seedlingstage it was 88.66% compared to primary forest and LOA <1year. Similarity index between LOA <1 year with LOA 5years, there were 60.26% for tree stage, 90.05% for pole stageand 51.13% for seedling stage.